diff --git a/apps/app_sms.c b/apps/app_sms.c
index 942b33c12a71913365d027357e007cef2a6580f2..8dd468b26ec2a77f1f4a9aada7aec24ad2983844 100644
--- a/apps/app_sms.c
+++ b/apps/app_sms.c
@@ -202,7 +202,7 @@ typedef struct sms_s {
 	char queue[30];              /*!< queue name */
 	char oa[20];                 /*!< originating address */
 	char da[20];                 /*!< destination address */
-	time_t scts;                 /*!< time stamp, UTC */
+	struct timeval scts;         /*!< time stamp, UTC */
 	unsigned char pid;           /*!< protocol ID */
 	unsigned char dcs;           /*!< data coding scheme */
 	short mr;                    /*!< message reference - actually a byte, but use -1 for not set */
@@ -766,7 +766,7 @@ static void sms_readfile(sms_t * h, char *fn)
 	h->rx = h->udl = *h->oa = *h->da = h->pid = h->srr = h->udhi = h->rp = h->vp = h->udhl = 0;
 	h->mr = -1;
 	h->dcs = 0xF1;			/* normal messages class 1 */
-	h->scts = time(NULL);
+	h->scts = ast_tvnow();
 	s = fopen(fn, "r");
 	if (s) {
 		if (unlink(fn)) {	/* concurrent access, we lost */
@@ -825,7 +825,7 @@ static void sms_readfile(sms_t * h, char *fn)
 						  M,
 						  S;
 						if (sscanf (p, "%d-%d-%dT%d:%d:%d", &Y, &m, &d, &H, &M, &S) == 6) {
-							struct tm t;
+							struct ast_tm t = { 0, };
 							t.tm_year = Y - 1900;
 							t.tm_mon = m - 1;
 							t.tm_mday = d;
@@ -833,8 +833,8 @@ static void sms_readfile(sms_t * h, char *fn)
 							t.tm_min = M;
 							t.tm_sec = S;
 							t.tm_isdst = -1;
-							h->scts = mktime(&t);
-							if (h->scts == (time_t) - 1)
+							h->scts = ast_mktime(&t, NULL);
+							if (h->scts.tv_sec == 0)
 								ast_log(LOG_WARNING, "Bad date/timein %s: %s", fn, p);
 						}
 					} else
@@ -925,7 +925,7 @@ static void sms_writefile(sms_t * h)
 	snprintf(fn, sizeof(fn), "%s/sms/%s", ast_config_AST_SPOOL_DIR, h->smsc ? h->rx ? "morx" : "mttx" : h->rx ? "mtrx" : "motx");
 	ast_mkdir(fn, 0777);			/* ensure it exists */
 	ast_copy_string(fn2, fn, sizeof(fn2));
-	snprintf(fn2 + strlen(fn2), sizeof(fn2) - strlen(fn2), "/%s.%s-%d", h->queue, isodate(h->scts, buf, sizeof(buf)), seq++);
+	snprintf(fn2 + strlen(fn2), sizeof(fn2) - strlen(fn2), "/%s.%s-%d", h->queue, isodate(h->scts.tv_sec, buf, sizeof(buf)), seq++);
 	snprintf(fn + strlen(fn), sizeof(fn) - strlen(fn), "/.%s", fn2 + strlen(fn) + 1);
 	o = fopen(fn, "w");
 	if (o == NULL)
@@ -982,9 +982,9 @@ static void sms_writefile(sms_t * h)
 			}
 		}
 	}
-	if (h->scts) {
+	if (h->scts.tv_sec) {
 		char buf[30];
-		fprintf(o, "scts=%s\n", isodate(h->scts, buf, sizeof(buf)));
+		fprintf(o, "scts=%s\n", isodate(h->scts.tv_sec, buf, sizeof(buf)));
 	}
 	if (h->pid)
 		fprintf(o, "pid=%d\n", h->pid);
@@ -1027,7 +1027,7 @@ static unsigned char sms_handleincoming (sms_t * h)
 			h->udhi = ((h->imsg[2] & 0x40) ? 1 : 0);
 			h->rp = ((h->imsg[2] & 0x80) ? 1 : 0);
 			ast_copy_string(h->oa, h->cli, sizeof(h->oa));
-			h->scts = time(NULL);
+			h->scts = ast_tvnow();
 			h->mr = h->imsg[p++];
 			p += unpackaddress(h->da, h->imsg + p);
 			h->pid = h->imsg[p++];
@@ -1065,7 +1065,7 @@ static unsigned char sms_handleincoming (sms_t * h)
 			p += unpackaddress(h->oa, h->imsg + p);
 			h->pid = h->imsg[p++];
 			h->dcs = h->imsg[p++];
-			h->scts = unpackdate(h->imsg + p);
+			h->scts.tv_sec = unpackdate(h->imsg + p);
 			p += 7;
 			p += unpacksms(h->dcs, h->imsg + p, h->udh, &h->udhl, h->ud, &h->udl, h->udhi);
 			h->rx = 1;				 /* received message */
@@ -1116,7 +1116,7 @@ static void putdummydata_proto2(sms_t *h)
 static void sms_compose2(sms_t *h, int more)
 {
 	struct ast_tm tm;
-	struct timeval tv = { h->scts, 0 };
+	struct timeval tv = h->scts;
 	char stm[9];
 
 	h->omsg[0] = 0x00;       /* set later... */
@@ -1171,7 +1171,7 @@ static int sms_handleincoming_proto2(sms_t *h)
 	/* ast_verb(3, "SMS-P2 Frame: %s\n", sms_hexdump(h->imsg, sz, debug_buf)); */
 
 	/* Parse message body (called payload) */
-	tv.tv_sec = h->scts = time(NULL);
+	tv = h->scts = ast_tvnow();
 	for (f = 4; f < sz; ) {
 		msg = h->imsg[f++];
 		msgsz = h->imsg[f++];
@@ -1186,7 +1186,7 @@ static int sms_handleincoming_proto2(sms_t *h)
 			h->udl = msgsz;
 			break;
 		case 0x14:      /* Date SCTS */
-			tv.tv_sec = h->scts = time(NULL);
+			tv = h->scts = ast_tvnow();
 			ast_localtime(&tv, &tm, NULL);
 			tm.tm_mon = ( (h->imsg[f] * 10) + h->imsg[f + 1] ) - 1;
 			tm.tm_mday = ( (h->imsg[f + 2] * 10) + h->imsg[f + 3] );
@@ -1302,7 +1302,7 @@ static void sms_compose1(sms_t *h, int more)
 		p += packaddress(h->omsg + p, h->oa);
 		h->omsg[p++] = h->pid;
 		h->omsg[p++] = h->dcs;
-		packdate(h->omsg + p, h->scts);
+		packdate(h->omsg + p, h->scts.tv_sec);
 		p += 7;
 		p += packsms(h->dcs, h->omsg + p, h->udhl, h->udh, h->udl, h->ud);
 	} else {			 /* submit */
@@ -1823,7 +1823,7 @@ static int sms_exec(struct ast_channel *chan, void *data)
 
 		/* submitting a message, not taking call. */
 		/* deprecated, use smsq instead */
-		h.scts = time(NULL);
+		h.scts = ast_tvnow();
 		if (ast_strlen_zero(sms_args.addr) || strlen(sms_args.addr) >= sizeof(h.oa)) {
 			ast_log(LOG_ERROR, "Address too long %s\n", sms_args.addr);
 			goto done;
diff --git a/funcs/func_strings.c b/funcs/func_strings.c
index 5eab9930f8814d81aac3d87c447ad103c6bf527b..db14c07fdb7036f917eaa4c91127acf981ed4981 100644
--- a/funcs/func_strings.c
+++ b/funcs/func_strings.c
@@ -659,7 +659,8 @@ static int acf_strptime(struct ast_channel *chan, const char *cmd, char *data,
 	if (!strptime(args.timestring, args.format, &t.time)) {
 		ast_log(LOG_WARNING, "C function strptime() output nothing?!!\n");
 	} else {
-		snprintf(buf, len, "%d", (int) ast_mktime(&t.atm, args.timezone));
+		struct timeval tv = ast_mktime(&t.atm, args.timezone);
+		snprintf(buf, len, "%d", (int) tv.tv_sec);
 	}
 
 	return 0;
diff --git a/include/asterisk/localtime.h b/include/asterisk/localtime.h
index cf2256ee65ff9935b8820edc80d814e4b5bc106d..4d46198c768540db4c0a5c5b2a7fedba084a9a40 100644
--- a/include/asterisk/localtime.h
+++ b/include/asterisk/localtime.h
@@ -40,11 +40,8 @@ struct ast_tm {
 	int tm_usec;        /* microseconds */
 };
 
-int ast_tzsetwall(void);
-void ast_tzset(const char *name);
 struct ast_tm *ast_localtime(const struct timeval *timep, struct ast_tm *p_tm, const char *zone);
-time_t ast_mktime(struct ast_tm * const tmp, const char *zone);
-char *ast_ctime(const struct timeval * const timep, char *buf);
+struct timeval ast_mktime(struct ast_tm * const tmp, const char *zone);
 int ast_strftime(char *buf, size_t len, const char *format, const struct ast_tm *tm);
 
 #endif /* _ASTERISK_LOCALTIME_H */
diff --git a/main/stdtime/localtime.c b/main/stdtime/localtime.c
index 4426feb97b3fdb5d783e36ebbb6b5580c48c26eb..94513ae762de8ea9dfe8ee8c7b95729b9a2d456a 100644
--- a/main/stdtime/localtime.c
+++ b/main/stdtime/localtime.c
@@ -26,21 +26,20 @@
 /*! \file
  *
  * Multi-timezone Localtime code
- * 
- * \author Leap second handling Bradley White (bww@k.gp.cs.cmu.edu).
- * \author POSIX-style TZ environment variable handling from Guy Harris (guy@auspex.com).
  *
+ * The original source from this file may be obtained from ftp://elsie.nci.nih.gov/pub/
  */
 
 /*
- * Asterisk defines
- *
- * Don't mess with these unless you're really sure you know what you're doing.
- */
-#ifndef _THREAD_SAFE
-#define _THREAD_SAFE
-#endif
-#define TZ_STRLEN_MAX	255
+** This file is in the public domain, so clarified as of
+** 1996-06-05 by Arthur David Olson.
+*/
+
+/*
+** Leap second handling from Bradley White.
+** POSIX-style TZ environment variable handling from Guy Harris.
+*/
+
 /* #define DEBUG */
 
 /*LINTLIBRARY*/
@@ -51,10 +50,11 @@
 #ifdef DEBUG
 #include <stdio.h>
 #endif
+#include <float.h>
+
 
 #include "private.h"
 #include "tzfile.h"
-
 #include "asterisk.h"
 
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
@@ -62,14 +62,27 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/lock.h"
 #include "asterisk/localtime.h"
 #include "asterisk/strings.h"
+#include "asterisk/linkedlists.h"
+#include "asterisk/utils.h"
 
 #ifndef lint
 #ifndef NOID
-static const char elsieid[] = "@(#)localtime.c	7.57";
+static char	__attribute__((unused)) elsieid[] = "@(#)localtime.c	8.5";
 #endif /* !defined NOID */
 #endif /* !defined lint */
 
+#ifndef TZ_ABBR_MAX_LEN
+#define TZ_ABBR_MAX_LEN	16
+#endif /* !defined TZ_ABBR_MAX_LEN */
+
+#ifndef TZ_ABBR_CHAR_SET
+#define TZ_ABBR_CHAR_SET \
+	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
+#endif /* !defined TZ_ABBR_CHAR_SET */
 
+#ifndef TZ_ABBR_ERR_CHAR
+#define TZ_ABBR_ERR_CHAR	'_'
+#endif /* !defined TZ_ABBR_ERR_CHAR */
 
 /*
 ** SunOS 4.1.1 headers lack O_BINARY.
@@ -82,55 +95,33 @@ static const char elsieid[] = "@(#)localtime.c	7.57";
 #define OPEN_MODE	O_RDONLY
 #endif /* !defined O_BINARY */
 
-#ifdef SOLARIS
-#undef TM_ZONE
-#undef TM_GMTOFF 
-#endif
+static const char	gmt[] = "GMT";
+static const struct timeval WRONG = { 0, 0 };
 
-#ifdef TM_ZONE
-#ifndef WILDABBR
 /*! \note
- * Someone might make incorrect use of a time zone abbreviation:
- *	1.	They might reference tzname[0] before calling ast_tzset (explicitly
- *		or implicitly).
- *	2.	They might reference tzname[1] before calling ast_tzset (explicitly
- *		or implicitly).
- *	3.	They might reference tzname[1] after setting to a time zone
- *		in which Daylight Saving Time is never observed.
- *	4.	They might reference tzname[0] after setting to a time zone
- *		in which Standard Time is never observed.
- *	5.	They might reference tm.TM_ZONE after calling offtime.
- * What's best to do in the above cases is open to debate;
- * for now, we just set things up so that in any of the five cases
- * WILDABBR is used.  Another possibility:  initialize tzname[0] to the
- * string "tzname[0] used before set", and similarly for the other cases.
- * And another:  initialize tzname[0] to "ERA", with an explanation in the
- * manual page of what this "time zone abbreviation" means (doing this so
- * that tzname[0] has the "normal" length of three characters).
+ * The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
+ * We default to US rules as of 1999-08-17.
+ * POSIX 1003.1 section 8.1.1 says that the default DST rules are
+ * implementation dependent; for historical reasons, US rules are a
+ * common default.
  */
-#define WILDABBR	"   "
-#endif /* !defined WILDABBR */
-
-static char		wildabbr[] = "WILDABBR";
-#endif /* TM_ZONE */
-
-/*! \brief FreeBSD defines 'zone' in 'struct tm' as non-const, so don't declare this
-   string as const. */
-static char		gmt[] = "GMT";
+#ifndef TZDEFRULESTRING
+#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
+#endif /* !defined TZDEFDST */
 
 /*!< \brief time type information */
-struct ttinfo {
-	long		tt_gmtoff;	/*!< GMT offset in seconds */
-	int		tt_isdst;	/*!< used to set tm_isdst */
-	int		tt_abbrind;	/*!< abbreviation list index */
-	int		tt_ttisstd;	/*!< TRUE if transition is std time */
-	int		tt_ttisgmt;	/*!< TRUE if transition is GMT */
+struct ttinfo {				/* time type information */
+	long		tt_gmtoff;	/* UTC offset in seconds */
+	int		tt_isdst;	/* used to set tm_isdst */
+	int		tt_abbrind;	/* abbreviation list index */
+	int		tt_ttisstd;	/* TRUE if transition is std time */
+	int		tt_ttisgmt;	/* TRUE if transition is UTC */
 };
 
 /*! \brief leap second information */
-struct lsinfo {
-	time_t		ls_trans;	/*!< transition time */
-	long		ls_corr;	/*!< correction to apply */
+struct lsinfo {				/* leap second information */
+	time_t		ls_trans;	/* transition time */
+	long		ls_corr;	/* correction to apply */
 };
 
 #define BIGGEST(a, b)	(((a) > (b)) ? (a) : (b))
@@ -141,119 +132,152 @@ struct lsinfo {
 #ifndef TZNAME_MAX
 #define MY_TZNAME_MAX	255
 #endif /* !defined TZNAME_MAX */
+#ifndef TZ_STRLEN_MAX
+#define TZ_STRLEN_MAX	255
+#endif /* !defined TZ_STRLEN_MAX */
 
 struct state {
-	char	name[TZ_STRLEN_MAX + 1];
+	/*! Name of the file that this references */
+	char    name[TZ_STRLEN_MAX + 1];
 	int		leapcnt;
 	int		timecnt;
 	int		typecnt;
 	int		charcnt;
+	int		goback;
+	int		goahead;
 	time_t		ats[TZ_MAX_TIMES];
 	unsigned char	types[TZ_MAX_TIMES];
 	struct ttinfo	ttis[TZ_MAX_TYPES];
 	char		chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
 				(2 * (MY_TZNAME_MAX + 1)))];
 	struct lsinfo	lsis[TZ_MAX_LEAPS];
-	struct state	*next;
+	AST_LIST_ENTRY(state) list;
 };
 
 struct rule {
-	int		r_type;		/*!< type of rule--see below */
-	int		r_day;		/*!< day number of rule */
-	int		r_week;		/*!< week number of rule */
-	int		r_mon;		/*!< month number of rule */
-	long		r_time;		/*!< transition time of rule */
+	int		r_type;		/* type of rule--see below */
+	int		r_day;		/* day number of rule */
+	int		r_week;		/* week number of rule */
+	int		r_mon;		/* month number of rule */
+	long		r_time;		/* transition time of rule */
 };
 
-#define JULIAN_DAY		0	/*!< Jn - Julian day */
-#define DAY_OF_YEAR		1	/*!< n - day of year */
-#define MONTH_NTH_DAY_OF_WEEK	2	/*!< Mm.n.d - month, week, day of week */
+#define JULIAN_DAY		0	/* Jn - Julian day */
+#define DAY_OF_YEAR		1	/* n - day of year */
+#define MONTH_NTH_DAY_OF_WEEK	2	/* Mm.n.d - month, week, day of week */
 
 /*
 ** Prototypes for static functions.
 */
 
 static long		detzcode P((const char * codep));
+static time_t		detzcode64 P((const char * codep));
+static int		differ_by_repeat P((time_t t1, time_t t0));
+static const char *	getzname P((const char * strp));
+static const char *	getqzname P((const char * strp, const int delim));
 static const char *	getnum P((const char * strp, int * nump, int min,
 				int max));
 static const char *	getsecs P((const char * strp, long * secsp));
 static const char *	getoffset P((const char * strp, long * offsetp));
 static const char *	getrule P((const char * strp, struct rule * rulep));
-static void		gmtload P((struct state * sp));
-static void		gmtsub P((const struct timeval * timep, long offset,
-				struct ast_tm * tmp, const char * zone));
-static void		localsub P((const struct timeval * timep, long offset,
-				struct ast_tm * tmp, const char * zone));
+static int		gmtload P((struct state * sp));
+static struct ast_tm *	gmtsub P((const struct timeval * timep, long offset,
+				struct ast_tm * tmp));
+static struct ast_tm *	localsub P((const struct timeval * timep, long offset,
+				struct ast_tm * tmp, const struct state *sp));
 static int		increment_overflow P((int * number, int delta));
+static int		leaps_thru_end_of P((int y));
+static int		long_increment_overflow P((long * number, int delta));
+static int		long_normalize_overflow P((long * tensptr,
+				int * unitsptr, const int base));
 static int		normalize_overflow P((int * tensptr, int * unitsptr,
-				int base));
-static time_t		time1 P((struct ast_tm * tmp,
-				void(*funcp) P((const struct timeval *,
-				long, struct ast_tm *, const char *)),
-				long offset, const char * zone));
-static time_t		time2 P((struct ast_tm *tmp,
-				void(*funcp) P((const struct timeval *,
-				long, struct ast_tm *, const char *)),
-				long offset, int * okayp, const char * zone));
-static void		timesub P((const struct timeval * timep, long offset,
-				const struct state * sp, struct ast_tm *tmp));
-static int		tmcomp P((const struct ast_tm *atmp,
+				const int base));
+static struct timeval	time1 P((struct ast_tm * tmp,
+				struct ast_tm * (*funcp) P((const struct timeval *,
+				long, struct ast_tm *, const struct state *sp)),
+				long offset, const struct state *sp));
+static struct timeval	time2 P((struct ast_tm *tmp,
+				struct ast_tm * (*funcp) P((const struct timeval *,
+				long, struct ast_tm*, const struct state *sp)),
+				long offset, int * okayp, const struct state *sp));
+static struct timeval	time2sub P((struct ast_tm *tmp,
+				struct ast_tm * (*funcp) (const struct timeval *,
+				long, struct ast_tm*, const struct state *sp),
+				long offset, int * okayp, int do_norm_secs, const struct state *sp));
+static struct ast_tm *	timesub P((const struct timeval * timep, long offset,
+				const struct state * sp, struct ast_tm * tmp));
+static int		tmcomp P((const struct ast_tm * atmp,
 				const struct ast_tm * btmp));
 static time_t		transtime P((time_t janfirst, int year,
 				const struct rule * rulep, long offset));
-static int		tzload P((const char * name, struct state * sp));
+static int		tzload P((const char * name, struct state * sp,
+				int doextend));
 static int		tzparse P((const char * name, struct state * sp,
 				int lastditch));
 
-static struct state *	lclptr      = NULL;
-static struct state *	last_lclptr = NULL;
-static struct state *	gmtptr      = NULL;
+static AST_LIST_HEAD_STATIC(zonelist, state);
 
 #ifndef TZ_STRLEN_MAX
 #define TZ_STRLEN_MAX 255
 #endif /* !defined TZ_STRLEN_MAX */
 
-static int		gmt_is_set;
-#ifdef	_THREAD_SAFE
-AST_MUTEX_DEFINE_STATIC(lcl_mutex);
-AST_MUTEX_DEFINE_STATIC(tzset_mutex);
-AST_MUTEX_DEFINE_STATIC(tzsetwall_mutex);
-AST_MUTEX_DEFINE_STATIC(gmt_mutex);
-#endif
-
-/*
+/*! \note
 ** Section 4.12.3 of X3.159-1989 requires that
 **	Except for the strftime function, these functions [asctime,
 **	ctime, gmtime, localtime] return values in one of two static
 **	objects: a broken-down time structure and an array of char.
-** Thanks to Paul Eggert (eggert@twinsun.com) for noting this.
+** Thanks to Paul Eggert for noting this.
 */
 
-static long detzcode(const char * const	codep)
+static long detzcode(const char * const codep)
 {
-	register long	result;
-	register int	i;
+	long	result;
+	int	i;
 
-	result = (codep[0] & 0x80) ? ~0L : 0L;
+	result = (codep[0] & 0x80) ? ~0L : 0;
 	for (i = 0; i < 4; ++i)
 		result = (result << 8) | (codep[i] & 0xff);
 	return result;
 }
 
-static int tzload(register const char *name, register struct state *const	sp)
+static time_t detzcode64(const char * const codep)
 {
-	register const char *	p;
-	register int		i;
-	register int		fid;
+	time_t	result;
+	int	i;
+
+	result = (codep[0] & 0x80) ?  (~(int_fast64_t) 0) : 0;
+	for (i = 0; i < 8; ++i)
+		result = result * 256 + (codep[i] & 0xff);
+	return result;
+}
+
+static int differ_by_repeat(const time_t t1, const time_t t0)
+{
+	const long long at1 = t1, at0 = t0;
+	if (TYPE_INTEGRAL(time_t) &&
+		TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
+			return 0;
+	return at1 - at0 == SECSPERREPEAT;
+}
+
+static int tzload(const char *name, struct state * const sp, const int doextend)
+{
+	const char *		p;
+	int			i;
+	int			fid;
+	int			stored;
+	int			nread;
+	union {
+		struct tzhead	tzhead;
+		char		buf[2 * sizeof(struct tzhead) +
+					2 * sizeof *sp +
+					4 * TZ_MAX_TIMES];
+	} u;
 
-#ifdef DEBUG
-	fprintf(stderr,"tzload called with name=%s, sp=%d\n", name, sp);
-#endif
 	if (name == NULL && (name = TZDEFAULT) == NULL)
 		return -1;
 	{
-		register int	doaccess;
-		struct stat	stab;
+		int	doaccess;
 		/*
 		** Section 4.9.1 of the C standard says that
 		** "FILENAME_MAX expands to an integral constant expression
@@ -261,7 +285,7 @@ static int tzload(register const char *name, register struct state *const	sp)
 		** to hold the longest file name string that the implementation
 		** guarantees can be opened."
 		*/
-		char		fullname[FILENAME_MAX + 1] = "";
+		char		fullname[FILENAME_MAX + 1];
 
 		if (name[0] == ':')
 			++name;
@@ -269,11 +293,11 @@ static int tzload(register const char *name, register struct state *const	sp)
 		if (!doaccess) {
 			if ((p = TZDIR) == NULL)
 				return -1;
-			if ((strlen(p) + 1 + strlen(name) + 1) >= sizeof fullname)
+			if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
 				return -1;
-			(void) strncpy(fullname, p, sizeof(fullname) - 1);
-			(void) strncat(fullname, "/", sizeof(fullname) - strlen(fullname) - 1);
-			(void) strncat(fullname, name, sizeof(fullname) - strlen(fullname) - 1);
+			(void) strcpy(fullname, p);
+			(void) strcat(fullname, "/");
+			(void) strcat(fullname, name);
 			/*
 			** Set doaccess if '.' (as in "../") shows up in name.
 			*/
@@ -282,37 +306,24 @@ static int tzload(register const char *name, register struct state *const	sp)
 			name = fullname;
 		}
 		if (doaccess && access(name, R_OK) != 0)
-		     	return -1;
-		if ((fid = open(name, OPEN_MODE)) == -1)
 			return -1;
-		if ((fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) {
-			close(fid);
+		if ((fid = open(name, OPEN_MODE)) == -1)
 			return -1;
-		}
 	}
-	{
-		struct tzhead *	tzhp;
-		char		buf[sizeof *sp + sizeof *tzhp];
+	nread = read(fid, u.buf, sizeof u.buf);
+	if (close(fid) < 0 || nread <= 0)
+		return -1;
+	for (stored = 4; stored <= 8; stored *= 2) {
 		int		ttisstdcnt;
 		int		ttisgmtcnt;
 
-		i = read(fid, buf, sizeof buf);
-		if (close(fid) != 0)
-			return -1;
-		p = buf;
-		p += (sizeof tzhp->tzh_magic) + (sizeof tzhp->tzh_reserved);
-		ttisstdcnt = (int) detzcode(p);
-		p += 4;
-		ttisgmtcnt = (int) detzcode(p);
-		p += 4;
-		sp->leapcnt = (int) detzcode(p);
-		p += 4;
-		sp->timecnt = (int) detzcode(p);
-		p += 4;
-		sp->typecnt = (int) detzcode(p);
-		p += 4;
-		sp->charcnt = (int) detzcode(p);
-		p += 4;
+		ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
+		ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
+		sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
+		sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
+		sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
+		sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
+		p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
 		if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
 			sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
 			sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
@@ -320,17 +331,19 @@ static int tzload(register const char *name, register struct state *const	sp)
 			(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
 			(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
 				return -1;
-		if (i - (p - buf) < sp->timecnt * 4 +	/* ats */
+		if (nread - (p - u.buf) <
+			sp->timecnt * stored +		/* ats */
 			sp->timecnt +			/* types */
-			sp->typecnt * (4 + 2) +		/* ttinfos */
+			sp->typecnt * 6 +		/* ttinfos */
 			sp->charcnt +			/* chars */
-			sp->leapcnt * (4 + 4) +		/* lsinfos */
+			sp->leapcnt * (stored + 4) +	/* lsinfos */
 			ttisstdcnt +			/* ttisstds */
 			ttisgmtcnt)			/* ttisgmts */
 				return -1;
 		for (i = 0; i < sp->timecnt; ++i) {
-			sp->ats[i] = detzcode(p);
-			p += 4;
+			sp->ats[i] = (stored == 4) ?
+				detzcode(p) : detzcode64(p);
+			p += stored;
 		}
 		for (i = 0; i < sp->timecnt; ++i) {
 			sp->types[i] = (unsigned char) *p++;
@@ -338,7 +351,7 @@ static int tzload(register const char *name, register struct state *const	sp)
 				return -1;
 		}
 		for (i = 0; i < sp->typecnt; ++i) {
-			register struct ttinfo *	ttisp;
+			struct ttinfo *	ttisp;
 
 			ttisp = &sp->ttis[i];
 			ttisp->tt_gmtoff = detzcode(p);
@@ -355,16 +368,17 @@ static int tzload(register const char *name, register struct state *const	sp)
 			sp->chars[i] = *p++;
 		sp->chars[i] = '\0';	/* ensure '\0' at end */
 		for (i = 0; i < sp->leapcnt; ++i) {
-			register struct lsinfo *	lsisp;
+			struct lsinfo *	lsisp;
 
 			lsisp = &sp->lsis[i];
-			lsisp->ls_trans = detzcode(p);
-			p += 4;
+			lsisp->ls_trans = (stored == 4) ?
+				detzcode(p) : detzcode64(p);
+			p += stored;
 			lsisp->ls_corr = detzcode(p);
 			p += 4;
 		}
 		for (i = 0; i < sp->typecnt; ++i) {
-			register struct ttinfo *	ttisp;
+			struct ttinfo *	ttisp;
 
 			ttisp = &sp->ttis[i];
 			if (ttisstdcnt == 0)
@@ -377,7 +391,7 @@ static int tzload(register const char *name, register struct state *const	sp)
 			}
 		}
 		for (i = 0; i < sp->typecnt; ++i) {
-			register struct ttinfo *	ttisp;
+			struct ttinfo *	ttisp;
 
 			ttisp = &sp->ttis[i];
 			if (ttisgmtcnt == 0)
@@ -389,7 +403,90 @@ static int tzload(register const char *name, register struct state *const	sp)
 						return -1;
 			}
 		}
+		/*
+		** Out-of-sort ats should mean we're running on a
+		** signed time_t system but using a data file with
+		** unsigned values (or vice versa).
+		*/
+		for (i = 0; i < sp->timecnt - 2; ++i)
+			if (sp->ats[i] > sp->ats[i + 1]) {
+				++i;
+				if (TYPE_SIGNED(time_t)) {
+					/*
+					** Ignore the end (easy).
+					*/
+					sp->timecnt = i;
+				} else {
+					/*
+					** Ignore the beginning (harder).
+					*/
+					int	j;
+
+					for (j = 0; j + i < sp->timecnt; ++j) {
+						sp->ats[j] = sp->ats[j + i];
+						sp->types[j] = sp->types[j + i];
+					}
+					sp->timecnt = j;
+				}
+				break;
+			}
+		/*
+		** If this is an old file, we're done.
+		*/
+		if (u.tzhead.tzh_version[0] == '\0')
+			break;
+		nread -= p - u.buf;
+		for (i = 0; i < nread; ++i)
+			u.buf[i] = p[i];
+		/*
+		** If this is a narrow integer time_t system, we're done.
+		*/
+		if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
+			break;
 	}
+	if (doextend && nread > 2 &&
+		u.buf[0] == '\n' && u.buf[nread - 1] == '\n' &&
+		sp->typecnt + 2 <= TZ_MAX_TYPES) {
+			struct state	ts;
+			int	result;
+
+			u.buf[nread - 1] = '\0';
+			result = tzparse(&u.buf[1], &ts, FALSE);
+			if (result == 0 && ts.typecnt == 2 &&
+				sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) {
+					for (i = 0; i < 2; ++i)
+						ts.ttis[i].tt_abbrind +=
+							sp->charcnt;
+					for (i = 0; i < ts.charcnt; ++i)
+						sp->chars[sp->charcnt++] =
+							ts.chars[i];
+					i = 0;
+					while (i < ts.timecnt &&
+						ts.ats[i] <=
+						sp->ats[sp->timecnt - 1])
+							++i;
+					while (i < ts.timecnt &&
+					    sp->timecnt < TZ_MAX_TIMES) {
+						sp->ats[sp->timecnt] =
+							ts.ats[i];
+						sp->types[sp->timecnt] =
+							sp->typecnt +
+							ts.types[i];
+						++sp->timecnt;
+						++i;
+					}
+					sp->ttis[sp->typecnt++] = ts.ttis[0];
+					sp->ttis[sp->typecnt++] = ts.ttis[1];
+			}
+	}
+	i = 2 * YEARSPERREPEAT;
+	sp->goback = sp->goahead = sp->timecnt > i;
+	sp->goback = sp->goback && sp->types[i] == sp->types[0] &&
+		differ_by_repeat(sp->ats[i], sp->ats[0]);
+	sp->goahead = sp->goahead &&
+		sp->types[sp->timecnt - 1] == sp->types[sp->timecnt - 1 - i] &&
+		differ_by_repeat(sp->ats[sp->timecnt - 1],
+			 sp->ats[sp->timecnt - 1 - i]);
 	return 0;
 }
 
@@ -403,16 +500,50 @@ static const int	year_lengths[2] = {
 };
 
 /*! \brief
- * Given a pointer into a time zone string, extract a number from that string.
- * \return Check that the number is within a specified range; if it is not, return
- * NULL.
- * Otherwise, return a pointer to the first character not part of the number.
+** Given a pointer into a time zone string, scan until a character that is not
+** a valid character in a zone name is found. Return a pointer to that
+** character.
+*/
+
+static const char * getzname(const char *strp)
+{
+	char	c;
+
+	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
+		c != '+')
+			++strp;
+	return strp;
+}
+
+/*! \brief
+** Given a pointer into an extended time zone string, scan until the ending
+** delimiter of the zone name is located. Return a pointer to the delimiter.
+**
+** As with getzname above, the legal character set is actually quite
+** restricted, with other characters producing undefined results.
+** We don't do any checking here; checking is done later in common-case code.
+*/
+
+static const char * getqzname(const char *strp, const int delim)
+{
+	int	c;
+
+	while ((c = *strp) != '\0' && c != delim)
+		++strp;
+	return strp;
+}
+
+/*! \brief
+** Given a pointer into a time zone string, extract a number from that string.
+** Check that the number is within a specified range; if it is not, return
+** NULL.
+** Otherwise, return a pointer to the first character not part of the number.
 */
 
-static const char *getnum(register const char *strp, int * const nump, const int min, const int max)
+static const char *getnum(const char *strp, int *nump, const int min, const int max)
 {
-	register char	c;
-	register int	num;
+	char	c;
+	int	num;
 
 	if (strp == NULL || !is_digit(c = *strp))
 		return NULL;
@@ -430,14 +561,14 @@ static const char *getnum(register const char *strp, int * const nump, const int
 }
 
 /*! \brief
- * Given a pointer into a time zone string, extract a number of seconds,
- * in hh[:mm[:ss]] form, from the string.
- * \return If any error occurs, return NULL.
- * Otherwise, return a pointer to the first character not part of the number
- * of seconds.
+** Given a pointer into a time zone string, extract a number of seconds,
+** in hh[:mm[:ss]] form, from the string.
+** If any error occurs, return NULL.
+** Otherwise, return a pointer to the first character not part of the number
+** of seconds.
 */
 
-static const char *getsecs(register const char *strp, long * const secsp)
+static const char *getsecs(const char *strp, long * const secsp)
 {
 	int	num;
 
@@ -459,7 +590,7 @@ static const char *getsecs(register const char *strp, long * const secsp)
 		*secsp += num * SECSPERMIN;
 		if (*strp == ':') {
 			++strp;
-			/* `SECSPERMIN' allows for leap seconds.  */
+			/* `SECSPERMIN' allows for leap seconds. */
 			strp = getnum(strp, &num, 0, SECSPERMIN);
 			if (strp == NULL)
 				return NULL;
@@ -470,15 +601,15 @@ static const char *getsecs(register const char *strp, long * const secsp)
 }
 
 /*! \brief
- * Given a pointer into a time zone string, extract an offset, in
- * [+-]hh[:mm[:ss]] form, from the string.
- * \return If any error occurs, return NULL.
- * Otherwise, return a pointer to the first character not part of the time.
+** Given a pointer into a time zone string, extract an offset, in
+** [+-]hh[:mm[:ss]] form, from the string.
+** If any error occurs, return NULL.
+** Otherwise, return a pointer to the first character not part of the time.
 */
 
-static const char * getoffset(register const char *strp, long * const offsetp)
+static const char *getoffset(const char *strp, long *offsetp)
 {
-	register int	neg = 0;
+	int	neg = 0;
 
 	if (*strp == '-') {
 		neg = 1;
@@ -494,13 +625,13 @@ static const char * getoffset(register const char *strp, long * const offsetp)
 }
 
 /*! \brief
- * Given a pointer into a time zone string, extract a rule in the form
- * date[/time].  See POSIX section 8 for the format of "date" and "time".
- * \return If a valid rule is not found, return NULL.
- * Otherwise, return a pointer to the first character not part of the rule.
+** Given a pointer into a time zone string, extract a rule in the form
+** date[/time]. See POSIX section 8 for the format of "date" and "time".
+** If a valid rule is not found, return NULL.
+** Otherwise, return a pointer to the first character not part of the rule.
 */
 
-static const char *getrule(const char *strp, register struct rule * const rulep)
+static const char *getrule(const char *strp, struct rule *rulep)
 {
 	if (*strp == 'J') {
 		/*
@@ -546,22 +677,19 @@ static const char *getrule(const char *strp, register struct rule * const rulep)
 }
 
 /*! \brief
- * Given the Epoch-relative time of January 1, 00:00:00 GMT, in a year, the
- * year, a rule, and the offset from GMT at the time that rule takes effect,
- * calculate the Epoch-relative time that rule takes effect.
+** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
+** year, a rule, and the offset from UTC at the time that rule takes effect,
+** calculate the Epoch-relative time that rule takes effect.
 */
 
-static time_t transtime(janfirst, year, rulep, offset)
-const time_t				janfirst;
-const int				year;
-register const struct rule * const	rulep;
-const long				offset;
+static time_t transtime(const time_t janfirst, const int year, const struct rule *rulep, const long offset)
 {
-	register int	leapyear;
-	register time_t	value = 0;
-	register int	i;
+	int	leapyear;
+	time_t	value;
+	int	i;
 	int		d, m1, yy0, yy1, yy2, dow;
 
+	INITIALIZE(value);
 	leapyear = isleap(year);
 	switch (rulep->r_type) {
 
@@ -609,7 +737,7 @@ const long				offset;
 			dow += DAYSPERWEEK;
 
 		/*
-		** "dow" is the day-of-week of the first day of the month.  Get
+		** "dow" is the day-of-week of the first day of the month. Get
 		** the day-of-month (zero-origin) of the first "dow" day of the
 		** month.
 		*/
@@ -631,54 +759,87 @@ const long				offset;
 	}
 
 	/*
-	** "value" is the Epoch-relative time of 00:00:00 GMT on the day in
-	** question.  To get the Epoch-relative time of the specified local
+	** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
+	** question. To get the Epoch-relative time of the specified local
 	** time on that day, add the transition time and the current offset
-	** from GMT.
+	** from UTC.
 	*/
 	return value + rulep->r_time + offset;
 }
 
-/*
+/*! \note
 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
 ** appropriate.
 */
 
-static int
-tzparse(name, sp, lastditch)
-const char *			name;
-register struct state * const	sp;
-const int			lastditch;
+static int tzparse(const char *name, struct state *sp, const int lastditch)
 {
 	const char *			stdname;
-	const char *			dstname = NULL;
-	size_t				stdlen = 0;
-	size_t				dstlen = 0;
-	long				stdoffset = 0L;
-	long				dstoffset = 0L;
-	register time_t *		atp;
-	register unsigned char *	typep;
-	register char *			cp;
-	register int			load_result;
-
+	const char *			dstname;
+	size_t				stdlen;
+	size_t				dstlen;
+	long				stdoffset;
+	long				dstoffset;
+	time_t *		atp;
+	unsigned char *	typep;
+	char *			cp;
+	int			load_result;
+
+	INITIALIZE(dstname);
 	stdname = name;
-#ifdef DEBUG
-	fprintf(stderr, "tzparse(): loading default rules\n");
-#endif
-	load_result = tzload(TZDEFRULES, sp);
+	if (lastditch) {
+		stdlen = strlen(name);	/* length of standard zone name */
+		name += stdlen;
+		if (stdlen >= sizeof sp->chars)
+			stdlen = (sizeof sp->chars) - 1;
+		stdoffset = 0;
+	} else {
+		if (*name == '<') {
+			name++;
+			stdname = name;
+			name = getqzname(name, '>');
+			if (*name != '>')
+				return -1;
+			stdlen = name - stdname;
+			name++;
+		} else {
+			name = getzname(name);
+			stdlen = name - stdname;
+		}
+		if (*name == '\0')
+			return -1;
+		name = getoffset(name, &stdoffset);
+		if (name == NULL)
+			return -1;
+	}
+	load_result = tzload(TZDEFRULES, sp, FALSE);
 	if (load_result != 0)
 		sp->leapcnt = 0;		/* so, we're off a little */
 	if (*name != '\0') {
+		if (*name == '<') {
+			dstname = ++name;
+			name = getqzname(name, '>');
+			if (*name != '>')
+				return -1;
+			dstlen = name - dstname;
+			name++;
+		} else {
+			dstname = name;
+			name = getzname(name);
+			dstlen = name - dstname; /* length of DST zone name */
+		}
 		if (*name != '\0' && *name != ',' && *name != ';') {
 			name = getoffset(name, &dstoffset);
 			if (name == NULL)
 				return -1;
 		} else	dstoffset = stdoffset - SECSPERHOUR;
+		if (*name == '\0' && load_result != 0)
+			name = TZDEFRULESTRING;
 		if (*name == ',' || *name == ';') {
 			struct rule	start;
 			struct rule	end;
-			register int	year;
-			register time_t	janfirst;
+			int	year;
+			time_t	janfirst;
 			time_t		starttime;
 			time_t		endtime;
 
@@ -693,11 +854,8 @@ const int			lastditch;
 				return -1;
 			sp->typecnt = 2;	/* standard time and DST */
 			/*
-			** Two transitions per year, from EPOCH_YEAR to 2037.
+			** Two transitions per year, from EPOCH_YEAR forward.
 			*/
-			sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
-			if (sp->timecnt > TZ_MAX_TIMES)
-				return -1;
 			sp->ttis[0].tt_gmtoff = -dstoffset;
 			sp->ttis[0].tt_isdst = 1;
 			sp->ttis[0].tt_abbrind = stdlen + 1;
@@ -707,7 +865,12 @@ const int			lastditch;
 			atp = sp->ats;
 			typep = sp->types;
 			janfirst = 0;
-			for (year = EPOCH_YEAR; year <= 2037; ++year) {
+			sp->timecnt = 0;
+			for (year = EPOCH_YEAR;
+			    sp->timecnt + 2 <= TZ_MAX_TIMES;
+			    ++year) {
+			    	time_t	newfirst;
+
 				starttime = transtime(janfirst, year, &start,
 					stdoffset);
 				endtime = transtime(janfirst, year, &end,
@@ -723,21 +886,24 @@ const int			lastditch;
 					*atp++ = endtime;
 					*typep++ = 1;	/* DST ends */
 				}
-				janfirst += year_lengths[isleap(year)] *
+				sp->timecnt += 2;
+				newfirst = janfirst;
+				newfirst += year_lengths[isleap(year)] *
 					SECSPERDAY;
+				if (newfirst <= janfirst)
+					break;
+				janfirst = newfirst;
 			}
 		} else {
-			register long	theirstdoffset;
-			register long	theirdstoffset;
-			register long	theiroffset;
-			register int	isdst;
-			register int	i;
-			register int	j;
+			long	theirstdoffset;
+			long	theirdstoffset;
+			long	theiroffset;
+			int	isdst;
+			int	i;
+			int	j;
 
 			if (*name != '\0')
 				return -1;
-			if (load_result != 0)
-				return -1;
 			/*
 			** Initial values of theirstdoffset and theirdstoffset.
 			*/
@@ -811,6 +977,7 @@ const int			lastditch;
 			sp->ttis[1].tt_gmtoff = -dstoffset;
 			sp->ttis[1].tt_isdst = TRUE;
 			sp->ttis[1].tt_abbrind = stdlen + 1;
+			sp->typecnt = 2;
 		}
 	} else {
 		dstlen = 0;
@@ -823,7 +990,7 @@ const int			lastditch;
 	sp->charcnt = stdlen + 1;
 	if (dstlen != 0)
 		sp->charcnt += dstlen + 1;
-	if (sp->charcnt > sizeof sp->chars)
+	if ((size_t) sp->charcnt > sizeof sp->chars)
 		return -1;
 	cp = sp->chars;
 	(void) strncpy(cp, stdname, stdlen);
@@ -836,202 +1003,124 @@ const int			lastditch;
 	return 0;
 }
 
-static void
-gmtload(sp)
-struct state * const	sp;
-{
-	if (tzload(gmt, sp) != 0)
-		(void) tzparse(gmt, sp, TRUE);
-}
-
-/*
-** A non-static declaration of ast_tzsetwall in a system header file
-** may cause a warning about this upcoming static declaration...
-*/
-static
-#ifdef	_THREAD_SAFE
-int
-ast_tzsetwall_basic P((void))
-#else
-int
-ast_tzsetwall P((void))
-#endif
+static int gmtload(struct state *sp)
 {
-	struct state *cur_state = lclptr;
-
-	/* Find the appropriate structure, if already parsed */
-	while (cur_state != NULL) {
-		if (cur_state->name[0] == '\0')
-			break;
-		cur_state = cur_state->next;
-	}
-	if (cur_state != NULL)
-		return 0;
-	cur_state = malloc(sizeof(struct state));
-	if (cur_state == NULL) {
-		return -1;
-	}
-	memset(cur_state,0,sizeof(struct state));
-	if (tzload((char *) NULL, cur_state) != 0)
-#ifdef DEBUG
-	{
-		fprintf(stderr, "ast_tzsetwall: calling gmtload()\n");
-#endif
-		gmtload(cur_state);
-#ifdef DEBUG
-	}
-#endif
-
-	if (last_lclptr)
-		last_lclptr->next = cur_state;
+	if (tzload(gmt, sp, TRUE) != 0)
+		return tzparse(gmt, sp, TRUE);
 	else
-		lclptr = cur_state;
-	last_lclptr = cur_state;
-	return 0;
+		return -1;
 }
 
-#ifdef	_THREAD_SAFE
-int
-ast_tzsetwall P((void))
+static const struct state *ast_tzset(const char *zone)
 {
-	ast_mutex_lock(&tzsetwall_mutex);
-	ast_tzsetwall_basic();
-	ast_mutex_unlock(&tzsetwall_mutex);
-	return 0;
-}
-#endif
+	struct state *sp;
 
-#ifdef	_THREAD_SAFE
-static int
-ast_tzset_basic P((const char *name))
-#else
-int
-ast_tzset P((const char *name))
-#endif
-{
-	struct state *cur_state = lclptr;
+	if (ast_strlen_zero(zone))
+		zone = "/etc/localtime";
 
-	/* Not set at all */
-	if (name == NULL) {
-		return ast_tzsetwall();
-	}
-
-	/* Find the appropriate structure, if already parsed */
-	while (cur_state != NULL) {
-		if (!strcmp(cur_state->name,name))
-			break;
-		cur_state = cur_state->next;
+	AST_LIST_LOCK(&zonelist);
+	AST_LIST_TRAVERSE(&zonelist, sp, list) {
+		if (!strcmp(sp->name, zone)) {
+			AST_LIST_UNLOCK(&zonelist);
+			return sp;
+		}
 	}
-	if (cur_state != NULL)
-		return 0;
+	AST_LIST_UNLOCK(&zonelist);
 
-	cur_state = malloc(sizeof(struct state));
-	if (cur_state == NULL) {
-		return -1;
-	}
-	memset(cur_state,0,sizeof(*cur_state));
+	if (!(sp = ast_calloc(1, sizeof *sp)))
+		return NULL;
 
-	/* Name is set, but set to the empty string == no adjustments */
-	if (name[0] == '\0') {
-		/*
-		** User wants it fast rather than right.
-		*/
-		cur_state->leapcnt = 0;		/* so, we're off a little */
-		cur_state->timecnt = 0;
-		cur_state->ttis[0].tt_gmtoff = 0;
-		cur_state->ttis[0].tt_abbrind = 0;
-		(void) strncpy(cur_state->chars, gmt, sizeof(cur_state->chars) - 1);
-	} else if (tzload(name, cur_state) != 0) {
-		if (name[0] == ':') {
-			(void) gmtload(cur_state);
-		} else if (tzparse(name, cur_state, FALSE) != 0) {
-			/* If not found, load localtime */
-			if (tzload("/etc/localtime", cur_state) != 0)
-				/* Last ditch, get GMT */
-				(void) gmtload(cur_state);
-		}
+	if (tzload(zone, sp, TRUE) != 0) {
+		if (zone[0] == ':' || tzparse(zone, sp, FALSE) != 0)
+			(void) gmtload(sp);
 	}
-	strncpy(cur_state->name, name, sizeof(cur_state->name) - 1);
-	if (last_lclptr)
-		last_lclptr->next = cur_state;
-	else
-		lclptr = cur_state;
-	last_lclptr = cur_state;
-	return 0;
+	ast_copy_string(sp->name, zone, sizeof(sp->name));
+	AST_LIST_LOCK(&zonelist);
+	AST_LIST_INSERT_TAIL(&zonelist, sp, list);
+	AST_LIST_UNLOCK(&zonelist);
+	return sp;
 }
 
-#ifdef	_THREAD_SAFE
-void
-ast_tzset P((const char *name))
-{
-	ast_mutex_lock(&tzset_mutex);
-	ast_tzset_basic(name);
-	ast_mutex_unlock(&tzset_mutex);
-}
-#endif
-
-/*
+/*! \note
 ** The easy way to behave "as if no library function calls" localtime
 ** is to not call it--so we drop its guts into "localsub", which can be
-** freely called.  (And no, the PANS doesn't require the above behavior--
+** freely called. (And no, the PANS doesn't require the above behavior--
 ** but it *is* desirable.)
 **
 ** The unused offset argument is for the benefit of mktime variants.
 */
 
-/*ARGSUSED*/
-static void
-localsub(timep, offset, tmp, zone)
-const struct timeval * const	timep;
-const long		offset;
-struct ast_tm * const	tmp;
-const char * const	zone;
+static struct ast_tm *localsub(const struct timeval *timep, const long offset, struct ast_tm *tmp, const struct state *sp)
 {
-	register struct state *		sp;
-	register const struct ttinfo *	ttisp;
-	register int			i;
+	const struct ttinfo *	ttisp;
+	int			i;
+	struct ast_tm *		result;
 	struct timeval	t;
 	memcpy(&t, timep, sizeof(t));
 
-	sp = lclptr;
-	/* Find the right zone record */
-	if (zone == NULL)
-		sp = NULL;
-	else
-		while (sp != NULL) {
-			if (!strcmp(sp->name,zone))
-				break;
-			sp = sp->next;
-		}
-
-	if (sp == NULL) {
-		ast_tzsetwall();
-		sp = lclptr;
-		/* Find the default zone record */
-		while (sp != NULL) {
-			if (sp->name[0] == '\0')
-				break;
-			sp = sp->next;
-		}
-	}
-
-	/* Last ditch effort, use GMT */
-	if (sp == NULL) {
-		gmtsub(timep, offset, tmp, zone);
-		return;
+	if (sp == NULL)
+		return gmtsub(timep, offset, tmp);
+	if ((sp->goback && t.tv_sec < sp->ats[0]) ||
+		(sp->goahead && t.tv_sec > sp->ats[sp->timecnt - 1])) {
+			struct timeval	newt = t;
+			time_t		seconds;
+			time_t		tcycles;
+			int_fast64_t	icycles;
+
+			if (t.tv_sec < sp->ats[0])
+				seconds = sp->ats[0] - t.tv_sec;
+			else	seconds = t.tv_sec - sp->ats[sp->timecnt - 1];
+			--seconds;
+			tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
+			++tcycles;
+			icycles = tcycles;
+			if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
+				return NULL;
+			seconds = icycles;
+			seconds *= YEARSPERREPEAT;
+			seconds *= AVGSECSPERYEAR;
+			if (t.tv_sec < sp->ats[0])
+				newt.tv_sec += seconds;
+			else	newt.tv_sec -= seconds;
+			if (newt.tv_sec < sp->ats[0] ||
+				newt.tv_sec > sp->ats[sp->timecnt - 1])
+					return NULL;	/* "cannot happen" */
+			result = localsub(&newt, offset, tmp, sp);
+			if (result == tmp) {
+				time_t	newy;
+
+				newy = tmp->tm_year;
+				if (t.tv_sec < sp->ats[0])
+					newy -= icycles * YEARSPERREPEAT;
+				else
+					newy += icycles * YEARSPERREPEAT;
+				tmp->tm_year = newy;
+				if (tmp->tm_year != newy)
+					return NULL;
+			}
+			return result;
 	}
 	if (sp->timecnt == 0 || t.tv_sec < sp->ats[0]) {
 		i = 0;
-		while (sp->ttis[i].tt_isdst)
+		while (sp->ttis[i].tt_isdst) {
 			if (++i >= sp->typecnt) {
 				i = 0;
 				break;
 			}
+		}
 	} else {
-		for (i = 1; i < sp->timecnt; ++i)
-			if (t.tv_sec < sp->ats[i])
-				break;
-		i = sp->types[i - 1];
+		int	lo = 1;
+		int	hi = sp->timecnt;
+
+		while (lo < hi) {
+			int	mid = (lo + hi) >> 1;
+
+			if (t.tv_sec < sp->ats[mid])
+				hi = mid;
+			else
+				lo = mid + 1;
+		}
+		i = (int) sp->types[lo - 1];
 	}
 	ttisp = &sp->ttis[i];
 	/*
@@ -1040,86 +1129,83 @@ const char * const	zone;
 	**	t += ttisp->tt_gmtoff;
 	**	timesub(&t, 0L, sp, tmp);
 	*/
-	timesub(&t, ttisp->tt_gmtoff, sp, tmp);
+	result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
 	tmp->tm_isdst = ttisp->tt_isdst;
-	tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
 #ifdef TM_ZONE
 	tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
 #endif /* defined TM_ZONE */
 	tmp->tm_usec = timep->tv_usec;
+	return result;
 }
 
-struct ast_tm *
-ast_localtime(timep, p_tm, zone)
-const struct timeval * const	timep;
-struct ast_tm *p_tm;
-const char * const	zone;
+struct ast_tm *ast_localtime(const struct timeval *timep, struct ast_tm *tmp, const char *zone)
 {
-#ifdef _THREAD_SAFE
-	ast_mutex_lock(&lcl_mutex);
-#endif
-	ast_tzset(ast_strlen_zero(zone) ? "/etc/localtime" : zone);
-	localsub(timep, 0L, p_tm, zone);
-#ifdef _THREAD_SAFE
-	ast_mutex_unlock(&lcl_mutex);
-#endif
-	return(p_tm);
+	const struct state *sp = ast_tzset(zone);
+	return sp ? localsub(timep, 0L, tmp, sp) : NULL;
 }
 
 /*
 ** gmtsub is to gmtime as localsub is to localtime.
 */
 
-static void
-gmtsub(timep, offset, tmp, zone)
-const struct timeval * const	timep;
-const long		offset;
-struct ast_tm * const	tmp;
-const char * const	zone;
+static struct ast_tm *gmtsub(const struct timeval *timep, const long offset, struct ast_tm *tmp)
 {
-#ifdef	_THREAD_SAFE
-	ast_mutex_lock(&gmt_mutex);
-#endif
-	if (!gmt_is_set) {
-		gmt_is_set = TRUE;
-		gmtptr = (struct state *) malloc(sizeof *gmtptr);
-		if (gmtptr != NULL)
-			gmtload(gmtptr);
+	struct ast_tm *	result;
+	struct state *sp;
+
+	AST_LIST_LOCK(&zonelist);
+	AST_LIST_TRAVERSE(&zonelist, sp, list) {
+		if (!strcmp(sp->name, "UTC"))
+			break;
 	}
-	ast_mutex_unlock(&gmt_mutex);
-	timesub(timep, offset, gmtptr, tmp);
+
+	if (!sp) {
+		if (!(sp = (struct state *) ast_calloc(1, sizeof *sp)))
+			return NULL;
+		gmtload(sp);
+		AST_LIST_INSERT_TAIL(&zonelist, sp, list);
+	}
+	AST_LIST_UNLOCK(&zonelist);
+
+	result = timesub(timep, offset, sp, tmp);
 #ifdef TM_ZONE
 	/*
 	** Could get fancy here and deliver something such as
-	** "GMT+xxxx" or "GMT-xxxx" if offset is non-zero,
+	** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
 	** but this is no time for a treasure hunt.
 	*/
 	if (offset != 0)
-		tmp->TM_ZONE = wildabbr;
-	else {
-		if (gmtptr == NULL)
-			tmp->TM_ZONE = gmt;
-		else	tmp->TM_ZONE = gmtptr->chars;
-	}
+		tmp->TM_ZONE = "    ";
+	else
+		tmp->TM_ZONE = sp->chars;
 #endif /* defined TM_ZONE */
+	return result;
 }
 
-static void
-timesub(timep, offset, sp, tmp)
-const struct timeval * const	timep;
-const long				offset;
-register const struct state * const	sp;
-register struct ast_tm * const		tmp;
+/*! \brief
+** Return the number of leap years through the end of the given year
+** where, to make the math easy, the answer for year zero is defined as zero.
+*/
+
+static int leaps_thru_end_of(const int y)
+{
+	return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
+		-(leaps_thru_end_of(-(y + 1)) + 1);
+}
+
+static struct ast_tm *timesub(const struct timeval *timep, const long offset, const struct state *sp, struct ast_tm *tmp)
 {
-	register const struct lsinfo *	lp;
-	register long			days;
-	register long			rem;
-	register int			y;
-	register int			yleap;
-	register const int *		ip;
-	register long			corr;
-	register int			hit;
-	register int			i;
+	const struct lsinfo *	lp;
+	time_t			tdays;
+	int			idays;	/* unsigned would be so 2003 */
+	long			rem;
+	int				y;
+	const int *		ip;
+	long			corr;
+	int			hit;
+	int			i;
+	long	seconds;
+
 
 	corr = 0;
 	hit = 0;
@@ -1144,94 +1230,108 @@ register struct ast_tm * const		tmp;
 			break;
 		}
 	}
-	days = timep->tv_sec / SECSPERDAY;
-	rem = timep->tv_sec % SECSPERDAY;
-#ifdef mc68k
-	if (timep->tv_sec == 0x80000000) {
-		/*
-		** A 3B1 muffs the division on the most negative number.
-		*/
-		days = -24855;
-		rem = -11648;
+	y = EPOCH_YEAR;
+	tdays = timep->tv_sec / SECSPERDAY;
+	rem = timep->tv_sec - tdays * SECSPERDAY;
+	while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
+		int		newy;
+		time_t	tdelta;
+		int	idelta;
+		int	leapdays;
+
+		tdelta = tdays / DAYSPERLYEAR;
+		idelta = tdelta;
+		if (tdelta - idelta >= 1 || idelta - tdelta >= 1)
+			return NULL;
+		if (idelta == 0)
+			idelta = (tdays < 0) ? -1 : 1;
+		newy = y;
+		if (increment_overflow(&newy, idelta))
+			return NULL;
+		leapdays = leaps_thru_end_of(newy - 1) -
+			leaps_thru_end_of(y - 1);
+		tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
+		tdays -= leapdays;
+		y = newy;
 	}
-#endif /* defined mc68k */
-	rem += (offset - corr);
+
+	seconds = tdays * SECSPERDAY + 0.5;
+	tdays = seconds / SECSPERDAY;
+	rem += seconds - tdays * SECSPERDAY;
+
+	/*
+	** Given the range, we can now fearlessly cast...
+	*/
+	idays = tdays;
+	rem += offset - corr;
 	while (rem < 0) {
 		rem += SECSPERDAY;
-		--days;
+		--idays;
 	}
 	while (rem >= SECSPERDAY) {
 		rem -= SECSPERDAY;
-		++days;
+		++idays;
+	}
+	while (idays < 0) {
+		if (increment_overflow(&y, -1))
+			return NULL;
+		idays += year_lengths[isleap(y)];
+	}
+	while (idays >= year_lengths[isleap(y)]) {
+		idays -= year_lengths[isleap(y)];
+		if (increment_overflow(&y, 1))
+			return NULL;
 	}
+	tmp->tm_year = y;
+	if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
+		return NULL;
+	tmp->tm_yday = idays;
+	/*
+	** The "extra" mods below avoid overflow problems.
+	*/
+	tmp->tm_wday = EPOCH_WDAY +
+		((y - EPOCH_YEAR) % DAYSPERWEEK) *
+		(DAYSPERNYEAR % DAYSPERWEEK) +
+		leaps_thru_end_of(y - 1) -
+		leaps_thru_end_of(EPOCH_YEAR - 1) +
+		idays;
+	tmp->tm_wday %= DAYSPERWEEK;
+	if (tmp->tm_wday < 0)
+		tmp->tm_wday += DAYSPERWEEK;
 	tmp->tm_hour = (int) (rem / SECSPERHOUR);
-	rem = rem % SECSPERHOUR;
+	rem %= SECSPERHOUR;
 	tmp->tm_min = (int) (rem / SECSPERMIN);
 	/*
 	** A positive leap second requires a special
-	** representation.  This uses "... ??:59:60" et seq.
+	** representation. This uses "... ??:59:60" et seq.
 	*/
 	tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
-	tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
-	if (tmp->tm_wday < 0)
-		tmp->tm_wday += DAYSPERWEEK;
-	y = EPOCH_YEAR;
-#define LEAPS_THRU_END_OF(y)	((y) / 4 - (y) / 100 + (y) / 400)
-	while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
-		register int	newy;
-
-		newy = y + days / DAYSPERNYEAR;
-		if (days < 0)
-			--newy;
-		days -= (newy - y) * DAYSPERNYEAR +
-			LEAPS_THRU_END_OF(newy - 1) -
-			LEAPS_THRU_END_OF(y - 1);
-		y = newy;
-	}
-	tmp->tm_year = y - TM_YEAR_BASE;
-	tmp->tm_yday = (int) days;
-	ip = mon_lengths[yleap];
-	for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
-		days = days - (long) ip[tmp->tm_mon];
-	tmp->tm_mday = (int) (days + 1);
+	ip = mon_lengths[isleap(y)];
+	for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
+		idays -= ip[tmp->tm_mon];
+	tmp->tm_mday = (int) (idays + 1);
 	tmp->tm_isdst = 0;
 #ifdef TM_GMTOFF
 	tmp->TM_GMTOFF = offset;
 #endif /* defined TM_GMTOFF */
 	tmp->tm_usec = timep->tv_usec;
+	return tmp;
 }
 
-char *
-ast_ctime(timep, buf)
-const struct timeval * const	timep;
-char *buf;
-{
-	struct ast_tm tm;
-	return asctime_r((struct tm *)ast_localtime(timep, &tm, NULL), buf);
-}
-
-/*
+/*! \note
 ** Adapted from code provided by Robert Elz, who writes:
 **	The "best" way to do mktime I think is based on an idea of Bob
 **	Kridle's (so its said...) from a long time ago.
-**	[kridle@xinet.com as of 1996-01-16.]
-**	It does a binary search of the time_t space.  Since time_t's are
+**	It does a binary search of the time_t space. Since time_t's are
 **	just 32 bits, its a max of 32 iterations (even at 64 bits it
 **	would still be very reasonable).
 */
 
-#ifndef WRONG
-#define WRONG	(-1)
-#endif /* !defined WRONG */
-
-/*
-** Simplified normalize logic courtesy Paul Eggert (eggert@twinsun.com).
+/*! \brief
+** Simplified normalize logic courtesy Paul Eggert.
 */
 
-static int
-increment_overflow(number, delta)
-int *	number;
-int	delta;
+static int increment_overflow(int *number, int delta)
 {
 	int	number0;
 
@@ -1240,13 +1340,18 @@ int	delta;
 	return (*number < number0) != (delta < 0);
 }
 
-static int
-normalize_overflow(tensptr, unitsptr, base)
-int * const	tensptr;
-int * const	unitsptr;
-const int	base;
+static int long_increment_overflow(long *number, int delta)
 {
-	register int	tensdelta;
+	long	number0;
+
+	number0 = *number;
+	*number += delta;
+	return (*number < number0) != (delta < 0);
+}
+
+static int normalize_overflow(int *tensptr, int *unitsptr, const int base)
+{
+	int	tensdelta;
 
 	tensdelta = (*unitsptr >= 0) ?
 		(*unitsptr / base) :
@@ -1255,79 +1360,95 @@ const int	base;
 	return increment_overflow(tensptr, tensdelta);
 }
 
-static int
-tmcomp(atmp, btmp)
-register const struct ast_tm * const atmp;
-register const struct ast_tm * const btmp;
+static int long_normalize_overflow(long *tensptr, int *unitsptr, const int base)
+{
+	int	tensdelta;
+
+	tensdelta = (*unitsptr >= 0) ?
+		(*unitsptr / base) :
+		(-1 - (-1 - *unitsptr) / base);
+	*unitsptr -= tensdelta * base;
+	return long_increment_overflow(tensptr, tensdelta);
+}
+
+static int tmcomp(const struct ast_tm *atmp, const struct ast_tm *btmp)
 {
-	register int	result;
+	int	result;
 
 	if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
 		(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
 		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
 		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
-		(result = (atmp->tm_min - btmp->tm_min)) == 0)
-			result = atmp->tm_sec - btmp->tm_sec;
+		(result = (atmp->tm_min - btmp->tm_min)) == 0 &&
+		(result = (atmp->tm_sec - btmp->tm_sec)) == 0)
+			result = atmp->tm_usec - btmp->tm_usec;
 	return result;
 }
 
-static time_t
-time2(tmp, funcp, offset, okayp, zone)
-struct ast_tm * const	tmp;
-void (* const		funcp) P((const struct timeval *, long, struct ast_tm*, const char*));
-const long		offset;
-int * const		okayp;
-const char * const	zone;
+static struct timeval time2sub(struct ast_tm *tmp, struct ast_tm * (* const funcp) (const struct timeval *, long, struct ast_tm *, const struct state *), const long offset, int *okayp, const int do_norm_secs, const struct state *sp)
 {
-	register const struct state *	sp;
-	register int			dir;
-	register int			bits;
-	register int			i, j ;
-	register int			saved_seconds;
+	int			dir;
+	int			i, j;
+	int			saved_seconds;
+	long			li;
+	time_t			lo;
+	time_t			hi;
+	long				y;
 	struct timeval			newt = { 0, 0 };
 	struct timeval			t = { 0, 0 };
 	struct ast_tm			yourtm, mytm;
 
 	*okayp = FALSE;
 	yourtm = *tmp;
+	if (do_norm_secs) {
+		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
+			SECSPERMIN))
+				return WRONG;
+	}
 	if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
 		return WRONG;
 	if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
 		return WRONG;
-	if (normalize_overflow(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR))
+	y = yourtm.tm_year;
+	if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR))
 		return WRONG;
 	/*
-	** Turn yourtm.tm_year into an actual year number for now.
+	** Turn y into an actual year number for now.
 	** It is converted back to an offset from TM_YEAR_BASE later.
 	*/
-	if (increment_overflow(&yourtm.tm_year, TM_YEAR_BASE))
+	if (long_increment_overflow(&y, TM_YEAR_BASE))
 		return WRONG;
 	while (yourtm.tm_mday <= 0) {
-		if (increment_overflow(&yourtm.tm_year, -1))
+		if (long_increment_overflow(&y, -1))
 			return WRONG;
-		i = yourtm.tm_year + (1 < yourtm.tm_mon);
-		yourtm.tm_mday += year_lengths[isleap(i)];
+		li = y + (1 < yourtm.tm_mon);
+		yourtm.tm_mday += year_lengths[isleap(li)];
 	}
 	while (yourtm.tm_mday > DAYSPERLYEAR) {
-		i = yourtm.tm_year + (1 < yourtm.tm_mon);
-		yourtm.tm_mday -= year_lengths[isleap(i)];
-		if (increment_overflow(&yourtm.tm_year, 1))
+		li = y + (1 < yourtm.tm_mon);
+		yourtm.tm_mday -= year_lengths[isleap(li)];
+		if (long_increment_overflow(&y, 1))
 			return WRONG;
 	}
 	for ( ; ; ) {
-		i = mon_lengths[isleap(yourtm.tm_year)][yourtm.tm_mon];
+		i = mon_lengths[isleap(y)][yourtm.tm_mon];
 		if (yourtm.tm_mday <= i)
 			break;
 		yourtm.tm_mday -= i;
 		if (++yourtm.tm_mon >= MONSPERYEAR) {
 			yourtm.tm_mon = 0;
-			if (increment_overflow(&yourtm.tm_year, 1))
+			if (long_increment_overflow(&y, 1))
 				return WRONG;
 		}
 	}
-	if (increment_overflow(&yourtm.tm_year, -TM_YEAR_BASE))
+	if (long_increment_overflow(&y, -TM_YEAR_BASE))
+		return WRONG;
+	yourtm.tm_year = y;
+	if (yourtm.tm_year != y)
 		return WRONG;
-	if (yourtm.tm_year + TM_YEAR_BASE < EPOCH_YEAR) {
+	if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
+		saved_seconds = 0;
+	else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
 		/*
 		** We can't set tm_sec to 0, because that might push the
 		** time below the minimum representable time.
@@ -1345,27 +1466,53 @@ const char * const	zone;
 		yourtm.tm_sec = 0;
 	}
 	/*
-	** Divide the search space in half
-	** (this works whether time_t is signed or unsigned).
-	*/
-	bits = TYPE_BIT(time_t) - 1;
-	/*
-	** If time_t is signed, then 0 is just above the median,
-	** assuming two's complement arithmetic.
-	** If time_t is unsigned, then (1 << bits) is just above the median.
+	** Do a binary search (this works whatever time_t's type is).
 	*/
-	t.tv_sec = 0;
+	if (!TYPE_SIGNED(time_t)) {
+		lo = 0;
+		hi = lo - 1;
+	} else if (!TYPE_INTEGRAL(time_t)) {
+		if (sizeof(time_t) > sizeof(float))
+			hi = (time_t) DBL_MAX;
+		else	hi = (time_t) FLT_MAX;
+		lo = -hi;
+	} else {
+		lo = 1;
+		for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
+			lo *= 2;
+		hi = -(lo + 1);
+	}
 	for ( ; ; ) {
-		(*funcp)(&t, offset, &mytm, zone);
-		dir = tmcomp(&mytm, &yourtm);
+		t.tv_sec = lo / 2 + hi / 2;
+		if (t.tv_sec < lo)
+			t.tv_sec = lo;
+		else if (t.tv_sec > hi)
+			t.tv_sec = hi;
+		if ((*funcp)(&t, offset, &mytm, sp) == NULL) {
+			/*
+			** Assume that t is too extreme to be represented in
+			** a struct ast_tm; arrange things so that it is less
+			** extreme on the next pass.
+			*/
+			dir = (t.tv_sec > 0) ? 1 : -1;
+		} else	dir = tmcomp(&mytm, &yourtm);
 		if (dir != 0) {
-			if (bits-- < 0)
+			if (t.tv_sec == lo) {
+				++t.tv_sec;
+				if (t.tv_sec <= lo)
+					return WRONG;
+				++lo;
+			} else if (t.tv_sec == hi) {
+				--t.tv_sec;
+				if (t.tv_sec >= hi)
+					return WRONG;
+				--hi;
+			}
+			if (lo > hi)
 				return WRONG;
-			if (bits < 0)
-				--t.tv_sec; /* may be needed if new t is minimal */
-			else if (dir > 0)
-				t.tv_sec -= ((time_t) 1) << bits;
-			else	t.tv_sec += ((time_t) 1) << bits;
+			if (dir > 0)
+				hi = t.tv_sec;
+			else	lo = t.tv_sec;
 			continue;
 		}
 		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
@@ -1379,11 +1526,6 @@ const char * const	zone;
 		/*
 		** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
 		*/
-		sp = (const struct state *)
-			(((void *) funcp == (void *) localsub) ?
-			lclptr : gmtptr);
-		if (sp == NULL)
-			return WRONG;
 		for (i = sp->typecnt - 1; i >= 0; --i) {
 			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
 				continue;
@@ -1392,7 +1534,8 @@ const char * const	zone;
 					continue;
 				newt.tv_sec = t.tv_sec + sp->ttis[j].tt_gmtoff -
 					sp->ttis[i].tt_gmtoff;
-				(*funcp)(&newt, offset, &mytm, zone);
+				if ((*funcp)(&newt, offset, &mytm, sp) == NULL)
+					continue;
 				if (tmcomp(&mytm, &yourtm) != 0)
 					continue;
 				if (mytm.tm_isdst != yourtm.tm_isdst)
@@ -1411,29 +1554,41 @@ label:
 	if ((newt.tv_sec < t.tv_sec) != (saved_seconds < 0))
 		return WRONG;
 	t.tv_sec = newt.tv_sec;
-	(*funcp)(&t, offset, tmp, zone);
-	*okayp = TRUE;
-	return t.tv_sec;
+	if ((*funcp)(&t, offset, tmp, sp))
+		*okayp = TRUE;
+	return t;
 }
 
-static time_t
-time1(tmp, funcp, offset, zone)
-struct ast_tm * const	tmp;
-void (* const		funcp) P((const struct timeval *, long, struct ast_tm *, const char*));
-const long		offset;
-const char * const	zone;
+static struct timeval time2(struct ast_tm *tmp, struct ast_tm * (* const funcp) (const struct timeval *, long, struct ast_tm*, const struct state *sp), const long offset, int *okayp, const struct state *sp)
 {
-	register time_t			t;
-	register const struct state *	sp;
-	register int			samei, otheri;
+	struct timeval	t;
+
+	/*! \note
+	** First try without normalization of seconds
+	** (in case tm_sec contains a value associated with a leap second).
+	** If that fails, try with normalization of seconds.
+	*/
+	t = time2sub(tmp, funcp, offset, okayp, FALSE, sp);
+	return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE, sp);
+}
+
+static struct timeval time1(struct ast_tm *tmp, struct ast_tm * (* const funcp) (const struct timeval *, long, struct ast_tm *, const struct state *), const long offset, const struct state *sp)
+{
+	struct timeval			t;
+	int			samei, otheri;
+	int			sameind, otherind;
+	int			i;
+	int			nseen;
+	int				seen[TZ_MAX_TYPES];
+	int				types[TZ_MAX_TYPES];
 	int				okay;
 
 	if (tmp->tm_isdst > 1)
 		tmp->tm_isdst = 1;
-	t = time2(tmp, funcp, offset, &okay, zone);
+	t = time2(tmp, funcp, offset, &okay, sp);
 #ifdef PCTS
 	/*
-	** PCTS code courtesy Grant Sullivan (grant@osf.org).
+	** PCTS code courtesy Grant Sullivan.
 	*/
 	if (okay)
 		return t;
@@ -1446,27 +1601,32 @@ const char * const	zone;
 #endif /* !defined PCTS */
 	/*
 	** We're supposed to assume that somebody took a time of one type
-	** and did some math on it that yielded a "struct tm" that's bad.
+	** and did some math on it that yielded a "struct ast_tm" that's bad.
 	** We try to divine the type they started from and adjust to the
 	** type they need.
 	*/
-	/*
-	** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
-	*/
-	sp = (const struct state *) (((void *) funcp == (void *) localsub) ?
-		lclptr : gmtptr);
 	if (sp == NULL)
 		return WRONG;
-	for (samei = sp->typecnt - 1; samei >= 0; --samei) {
+	for (i = 0; i < sp->typecnt; ++i)
+		seen[i] = FALSE;
+	nseen = 0;
+	for (i = sp->timecnt - 1; i >= 0; --i)
+		if (!seen[sp->types[i]]) {
+			seen[sp->types[i]] = TRUE;
+			types[nseen++] = sp->types[i];
+		}
+	for (sameind = 0; sameind < nseen; ++sameind) {
+		samei = types[sameind];
 		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
 			continue;
-		for (otheri = sp->typecnt - 1; otheri >= 0; --otheri) {
+		for (otherind = 0; otherind < nseen; ++otherind) {
+			otheri = types[otherind];
 			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
 				continue;
 			tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
 					sp->ttis[samei].tt_gmtoff;
 			tmp->tm_isdst = !tmp->tm_isdst;
-			t = time2(tmp, funcp, offset, &okay, zone);
+			t = time2(tmp, funcp, offset, &okay, sp);
 			if (okay)
 				return t;
 			tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
@@ -1477,21 +1637,12 @@ const char * const	zone;
 	return WRONG;
 }
 
-time_t
-ast_mktime(tmp,zone)
-struct ast_tm * const	tmp;
-const char * const	zone;
+struct timeval ast_mktime(struct ast_tm *tmp, const char *zone)
 {
-	time_t mktime_return_value;
-#ifdef	_THREAD_SAFE
-	ast_mutex_lock(&lcl_mutex);
-#endif
-	ast_tzset(!ast_strlen_zero(zone) ? zone : "/etc/localtime");
-	mktime_return_value = time1(tmp, localsub, 0L, !ast_strlen_zero(zone) ? zone : "/etc/localtime");
-#ifdef	_THREAD_SAFE
-	ast_mutex_unlock(&lcl_mutex);
-#endif
-	return(mktime_return_value);
+	const struct state *sp;
+	if (!(sp = ast_tzset(zone)))
+		return WRONG;
+	return time1(tmp, localsub, 0L, sp);
 }
 
 int ast_strftime(char *buf, size_t len, const char *tmp, const struct ast_tm *tm)
diff --git a/main/stdtime/private.h b/main/stdtime/private.h
index 8ef9ccfddeaf6fc5eef17ebe1d35b2a2d6f4dd4c..11793088d7801c1e2ebe18228f509d20e1195fd8 100644
--- a/main/stdtime/private.h
+++ b/main/stdtime/private.h
@@ -1,31 +1,11 @@
-/* $FreeBSD: src/lib/libc/stdtime/private.h,v 1.6.8.1 2000/08/23 00:19:15 jhb Exp $ */
-
 #ifndef PRIVATE_H
 
 #define PRIVATE_H
+
 /*
 ** This file is in the public domain, so clarified as of
-** June 5, 1996 by Arthur David Olson (arthur_david_olson@nih.gov).
-*/
-
-/* Stuff moved from Makefile.inc to reduce clutter */
-#ifndef __CYGWIN__
-#ifndef TM_GMTOFF
-#define TM_GMTOFF	tm_gmtoff
-#define TM_ZONE		tm_zone
-#endif
-#define STD_INSPIRED	1
-#define PCTS		1
-#define HAVE_LONG_DOUBLE 1
-#define HAVE_STRERROR	1
-#define	HAVE_UNISTD_H	1
-#define	LOCALE_HOME	_PATH_LOCALE
-#ifdef SOLARIS
-#define TZDIR		"/usr/share/lib/zoneinfo"
-#else
-#define TZDIR		"/usr/share/zoneinfo"
-#endif /* def SOLARIS */
-#endif /* ndef TM_GMTOFF */
+** 1996-06-05 by Arthur David Olson.
+*/
 
 /*
 ** This header is for use ONLY with the time conversion code.
@@ -41,12 +21,12 @@
 
 #ifndef lint
 #ifndef NOID
-/*
-static char	privatehid[] = "@(#)private.h	7.43";
-*/
+static char	__attribute__((unused)) privatehid[] = "@(#)private.h	8.3";
 #endif /* !defined NOID */
 #endif /* !defined lint */
 
+#define GRANDPARENTED	"Local time zone must be set--see zic manual page"
+
 /*
 ** Defaults for preprocessor symbols.
 ** You can override these in your C compiler options, e.g. `-DHAVE_ADJTIME=0'.
@@ -60,14 +40,30 @@ static char	privatehid[] = "@(#)private.h	7.43";
 #define HAVE_GETTEXT		0
 #endif /* !defined HAVE_GETTEXT */
 
+#ifndef HAVE_INCOMPATIBLE_CTIME_R
+#define HAVE_INCOMPATIBLE_CTIME_R	0
+#endif /* !defined INCOMPATIBLE_CTIME_R */
+
 #ifndef HAVE_SETTIMEOFDAY
 #define HAVE_SETTIMEOFDAY	3
 #endif /* !defined HAVE_SETTIMEOFDAY */
 
 #ifndef HAVE_STRERROR
-#define HAVE_STRERROR		0
+#define HAVE_STRERROR		1
 #endif /* !defined HAVE_STRERROR */
 
+#ifndef HAVE_SYMLINK
+#define HAVE_SYMLINK		1
+#endif /* !defined HAVE_SYMLINK */
+
+#ifndef HAVE_SYS_STAT_H
+#define HAVE_SYS_STAT_H		1
+#endif /* !defined HAVE_SYS_STAT_H */
+
+#ifndef HAVE_SYS_WAIT_H
+#define HAVE_SYS_WAIT_H		1
+#endif /* !defined HAVE_SYS_WAIT_H */
+
 #ifndef HAVE_UNISTD_H
 #define HAVE_UNISTD_H		1
 #endif /* !defined HAVE_UNISTD_H */
@@ -80,6 +76,11 @@ static char	privatehid[] = "@(#)private.h	7.43";
 #define LOCALE_HOME		"/usr/lib/locale"
 #endif /* !defined LOCALE_HOME */
 
+#if HAVE_INCOMPATIBLE_CTIME_R
+#define asctime_r _incompatible_asctime_r
+#define ctime_r _incompatible_ctime_r
+#endif /* HAVE_INCOMPATIBLE_CTIME_R */
+
 /*
 ** Nested includes
 */
@@ -88,43 +89,105 @@ static char	privatehid[] = "@(#)private.h	7.43";
 #include "stdio.h"
 #include "errno.h"
 #include "string.h"
-#include "limits.h"	/* for CHAR_BIT */
+#include "limits.h"	/* for CHAR_BIT et al. */
 #include "time.h"
 #include "stdlib.h"
 
-#if HAVE_GETTEXT - 0
+#if HAVE_GETTEXT
 #include "libintl.h"
-#endif /* HAVE_GETTEXT - 0 */
+#endif /* HAVE_GETTEXT */
+
+#if HAVE_SYS_WAIT_H
+#include <sys/wait.h>	/* for WIFEXITED and WEXITSTATUS */
+#endif /* HAVE_SYS_WAIT_H */
+
+#ifndef WIFEXITED
+#define WIFEXITED(status)	(((status) & 0xff) == 0)
+#endif /* !defined WIFEXITED */
+#ifndef WEXITSTATUS
+#define WEXITSTATUS(status)	(((status) >> 8) & 0xff)
+#endif /* !defined WEXITSTATUS */
 
-#if HAVE_UNISTD_H - 0
+#if HAVE_UNISTD_H
 #include "unistd.h"	/* for F_OK and R_OK */
-#endif /* HAVE_UNISTD_H - 0 */
+#endif /* HAVE_UNISTD_H */
 
-#if !(HAVE_UNISTD_H - 0)
+#if !HAVE_UNISTD_H
 #ifndef F_OK
 #define F_OK	0
 #endif /* !defined F_OK */
 #ifndef R_OK
 #define R_OK	4
 #endif /* !defined R_OK */
-#endif /* !(HAVE_UNISTD_H - 0) */
+#endif /* !HAVE_UNISTD_H */
 
-/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX.  */
+/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */
 #define is_digit(c) ((unsigned)(c) - '0' <= 9)
 
+/*
+** Define HAVE_STDINT_H's default value here, rather than at the
+** start, since __GLIBC__'s value depends on previously-included
+** files.
+** (glibc 2.1 and later have stdint.h, even with pre-C99 compilers.)
+*/
+#ifndef HAVE_STDINT_H
+#define HAVE_STDINT_H \
+	(199901 <= __STDC_VERSION__ || \
+	2 < (__GLIBC__ + (0 < __GLIBC_MINOR__)))
+#endif /* !defined HAVE_STDINT_H */
+
+#if HAVE_STDINT_H
+#include "stdint.h"
+#endif /* !HAVE_STDINT_H */
+
+#ifndef INT_FAST64_MAX
+/* Pre-C99 GCC compilers define __LONG_LONG_MAX__ instead of LLONG_MAX.  */
+#if defined LLONG_MAX || defined __LONG_LONG_MAX__
+typedef long long	int_fast64_t;
+#else /* ! (defined LLONG_MAX || defined __LONG_LONG_MAX__) */
+#if (LONG_MAX >> 31) < 0xffffffff
+Please use a compiler that supports a 64-bit integer type (or wider);
+you may need to compile with "-DHAVE_STDINT_H".
+#endif /* (LONG_MAX >> 31) < 0xffffffff */
+typedef long		int_fast64_t;
+#endif /* ! (defined LLONG_MAX || defined __LONG_LONG_MAX__) */
+#endif /* !defined INT_FAST64_MAX */
+
+#ifndef INT32_MAX
+#define INT32_MAX 0x7fffffff
+#endif /* !defined INT32_MAX */
+#ifndef INT32_MIN
+#define INT32_MIN (-1 - INT32_MAX)
+#endif /* !defined INT32_MIN */
+
 /*
 ** Workarounds for compilers/systems.
 */
 
+/*
+** If your compiler lacks prototypes, "#define P(x) ()".
+*/
+
 #ifndef P
-#ifdef __STDC__
 #define P(x)	x
-#endif /* defined __STDC__ */
-#ifndef __STDC__
-#define P(x)	()
-#endif /* !defined __STDC__ */
 #endif /* !defined P */
 
+/*
+** SunOS 4.1.1 headers lack EXIT_SUCCESS.
+*/
+
+#ifndef EXIT_SUCCESS
+#define EXIT_SUCCESS	0
+#endif /* !defined EXIT_SUCCESS */
+
+/*
+** SunOS 4.1.1 headers lack EXIT_FAILURE.
+*/
+
+#ifndef EXIT_FAILURE
+#define EXIT_FAILURE	1
+#endif /* !defined EXIT_FAILURE */
+
 /*
 ** SunOS 4.1.1 headers lack FILENAME_MAX.
 */
@@ -146,6 +209,38 @@ static char	privatehid[] = "@(#)private.h	7.43";
 
 #endif /* !defined FILENAME_MAX */
 
+/*
+** SunOS 4.1.1 libraries lack remove.
+*/
+
+#ifndef remove
+extern int	unlink P((const char * filename));
+#define remove	unlink
+#endif /* !defined remove */
+
+/*
+** Some ancient errno.h implementations don't declare errno.
+** But some newer errno.h implementations define it as a macro.
+** Fix the former without affecting the latter.
+*/
+
+#ifndef errno
+extern int errno;
+#endif /* !defined errno */
+
+/*
+** Private function declarations.
+*/
+
+char *		icalloc P((int nelem, int elsize));
+char *		icatalloc P((char * old, const char * new));
+char *		icpyalloc P((const char * string));
+char *		imalloc P((int n));
+void *		irealloc P((void * pointer, int size));
+void		icfree P((char * pointer));
+void		ifree P((char * pointer));
+const char *	scheck P((const char * string, const char * format));
+
 /*
 ** Finally, some convenience items.
 */
@@ -166,6 +261,15 @@ static char	privatehid[] = "@(#)private.h	7.43";
 #define TYPE_SIGNED(type) (((type) -1) < 0)
 #endif /* !defined TYPE_SIGNED */
 
+/*
+** Since the definition of TYPE_INTEGRAL contains floating point numbers,
+** it cannot be used in preprocessor directives.
+*/
+
+#ifndef TYPE_INTEGRAL
+#define TYPE_INTEGRAL(type) (((type) 0.5) != 0.5)
+#endif /* !defined TYPE_INTEGRAL */
+
 #ifndef INT_STRLEN_MAXIMUM
 /*
 ** 302 / 1000 is log10(2.0) rounded up.
@@ -174,7 +278,8 @@ static char	privatehid[] = "@(#)private.h	7.43";
 ** add one more for a minus sign if the type is signed.
 */
 #define INT_STRLEN_MAXIMUM(type) \
-    ((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + 1 + TYPE_SIGNED(type))
+	((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
+	1 + TYPE_SIGNED(type))
 #endif /* !defined INT_STRLEN_MAXIMUM */
 
 /*
@@ -208,19 +313,46 @@ static char	privatehid[] = "@(#)private.h	7.43";
 */
 
 #ifndef _
-#if HAVE_GETTEXT - 0
+#if HAVE_GETTEXT
 #define _(msgid) gettext(msgid)
-#else /* !(HAVE_GETTEXT - 0) */
+#else /* !HAVE_GETTEXT */
 #define _(msgid) msgid
-#endif /* !(HAVE_GETTEXT - 0) */
+#endif /* !HAVE_GETTEXT */
 #endif /* !defined _ */
 
 #ifndef TZ_DOMAIN
 #define TZ_DOMAIN "tz"
 #endif /* !defined TZ_DOMAIN */
 
+#if HAVE_INCOMPATIBLE_CTIME_R
+#undef asctime_r
+#undef ctime_r
+char *asctime_r P((struct tm const *, char *));
+char *ctime_r P((time_t const *, char *));
+#endif /* HAVE_INCOMPATIBLE_CTIME_R */
+
+#ifndef YEARSPERREPEAT
+#define YEARSPERREPEAT		400	/* years before a Gregorian repeat */
+#endif /* !defined YEARSPERREPEAT */
+
+/*
+** The Gregorian year averages 365.2425 days, which is 31556952 seconds.
+*/
+
+#ifndef AVGSECSPERYEAR
+#define AVGSECSPERYEAR		31556952L
+#endif /* !defined AVGSECSPERYEAR */
+
+#ifndef SECSPERREPEAT
+#define SECSPERREPEAT		((int_fast64_t) YEARSPERREPEAT * (int_fast64_t) AVGSECSPERYEAR)
+#endif /* !defined SECSPERREPEAT */
+
+#ifndef SECSPERREPEAT_BITS
+#define SECSPERREPEAT_BITS	34	/* ceil(log2(SECSPERREPEAT)) */
+#endif /* !defined SECSPERREPEAT_BITS */
+
 /*
-** UNIX was a registered trademark of UNIX System Laboratories in 1993.
+** UNIX was a registered trademark of The Open Group in 2003.
 */
 
 #endif /* !defined PRIVATE_H */
diff --git a/main/stdtime/tzfile.h b/main/stdtime/tzfile.h
index f16d5a05c95e540c273e347a79640b0d3e342207..2637ab960d8eca7b97cdc15aca2c7a0abc84af02 100644
--- a/main/stdtime/tzfile.h
+++ b/main/stdtime/tzfile.h
@@ -2,17 +2,18 @@
 
 #define TZFILE_H
 
-/*! \brief
- * This file is in the public domain, so clarified as of
- * 1996-06-05 by 
- * \author Arthur David Olson (arthur_david_olson@nih.gov).
- *
- * \note This header is for use ONLY with the time conversion code.
- * There is no guarantee that it will remain unchanged,
- * or that it will remain at all.
- * Do NOT copy it to any system include directory.
- * Thank you!
- */
+/*
+** This file is in the public domain, so clarified as of
+** 1996-06-05 by Arthur David Olson.
+*/
+
+/*
+** This header is for use ONLY with the time conversion code.
+** There is no guarantee that it will remain unchanged,
+** or that it will remain at all.
+** Do NOT copy it to any system include directory.
+** Thank you!
+*/
 
 /*
 ** ID
@@ -20,9 +21,7 @@
 
 #ifndef lint
 #ifndef NOID
-/*
-static char	tzfilehid[] = "@(#)tzfile.h	7.14";
-*/
+static char	__attribute__((unused)) tzfilehid[] = "@(#)tzfile.h	8.1";
 #endif /* !defined NOID */
 #endif /* !defined lint */
 
@@ -31,11 +30,19 @@ static char	tzfilehid[] = "@(#)tzfile.h	7.14";
 */
 
 #ifndef TZDIR
-#define TZDIR	"/usr/share/zoneinfo" /*!< Time zone object file directory */
+#ifdef SOLARIS
+#define TZDIR	"/usr/share/lib/zoneinfo"
+#else
+#ifdef FREEBSD
+#define TZDIR	"/usr/local/etc/zoneinfo" /* Time zone object file directory */
+#else
+#define TZDIR	"/usr/share/zoneinfo"
+#endif /* defined FREEBSD */
+#endif /* defined SOLARIS */
 #endif /* !defined TZDIR */
 
 #ifndef TZDEFAULT
-#define TZDEFAULT	"/etc/localtime"
+#define TZDEFAULT	"localtime"
 #endif /* !defined TZDEFAULT */
 
 #ifndef TZDEFRULES
@@ -49,8 +56,9 @@ static char	tzfilehid[] = "@(#)tzfile.h	7.14";
 #define	TZ_MAGIC	"TZif"
 
 struct tzhead {
- 	char	tzh_magic[4];		/* TZ_MAGIC */
-	char	tzh_reserved[16];	/* reserved for future use */
+	char	tzh_magic[4];		/* TZ_MAGIC */
+	char	tzh_version[1];		/* '\0' or '2' as of 2005 */
+	char	tzh_reserved[15];	/* reserved--must be zero */
 	char	tzh_ttisgmtcnt[4];	/* coded number of trans. time flags */
 	char	tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
 	char	tzh_leapcnt[4];		/* coded number of leap seconds */
@@ -84,19 +92,23 @@ struct tzhead {
 **					assumed to be local time
 */
 
+/*
+** If tzh_version is '2' or greater, the above is followed by a second instance
+** of tzhead and a second instance of the data in which each coded transition
+** time uses 8 rather than 4 chars,
+** then a POSIX-TZ-environment-variable-style string for use in handling
+** instants after the last transition time stored in the file
+** (with nothing between the newlines if there is no POSIX representation for
+** such instants).
+*/
+
 /*
 ** In the current implementation, "tzset()" refuses to deal with files that
 ** exceed any of the limits below.
 */
 
 #ifndef TZ_MAX_TIMES
-/*
-** The TZ_MAX_TIMES value below is enough to handle a bit more than a
-** year's worth of solar time (corrected daily to the nearest second) or
-** 138 years of Pacific Presidential Election time
-** (where there are three time zone transitions every fourth year).
-*/
-#define TZ_MAX_TIMES	370
+#define TZ_MAX_TIMES	1200
 #endif /* !defined TZ_MAX_TIMES */
 
 #ifndef TZ_MAX_TYPES
@@ -106,7 +118,7 @@ struct tzhead {
 #ifdef NOSOLAR
 /*
 ** Must be at least 14 for Europe/Riga as of Jan 12 1995,
-** as noted by Earl Chew <earl@hpato.aus.hp.com>.
+** as noted by Earl Chew.
 */
 #define TZ_MAX_TYPES	20	/* Maximum number of local time types */
 #endif /* !defined NOSOLAR */
@@ -157,33 +169,20 @@ struct tzhead {
 #define EPOCH_YEAR	1970
 #define EPOCH_WDAY	TM_THURSDAY
 
-/*
-** Accurate only for the past couple of centuries;
-** that will probably do.
-*/
-
 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
 
-#ifndef USG
-
 /*
-** Use of the underscored variants may cause problems if you move your code to
-** certain System-V-based systems; for maximum portability, use the
-** underscore-free variants.  The underscored variants are provided for
-** backward compatibility only; they may disappear from future versions of
-** this file.
+** Since everything in isleap is modulo 400 (or a factor of 400), we know that
+**	isleap(y) == isleap(y % 400)
+** and so
+**	isleap(a + b) == isleap((a + b) % 400)
+** or
+**	isleap(a + b) == isleap(a % 400 + b % 400)
+** This is true even if % means modulo rather than Fortran remainder
+** (which is allowed by C89 but not C99).
+** We use this to avoid addition overflow problems.
 */
 
-#define SECS_PER_MIN	SECSPERMIN
-#define MINS_PER_HOUR	MINSPERHOUR
-#define HOURS_PER_DAY	HOURSPERDAY
-#define DAYS_PER_WEEK	DAYSPERWEEK
-#define DAYS_PER_NYEAR	DAYSPERNYEAR
-#define DAYS_PER_LYEAR	DAYSPERLYEAR
-#define SECS_PER_HOUR	SECSPERHOUR
-#define SECS_PER_DAY	SECSPERDAY
-#define MONS_PER_YEAR	MONSPERYEAR
-
-#endif /* !defined USG */
+#define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
 
 #endif /* !defined TZFILE_H */