diff --git a/doc/README.variables b/doc/README.variables
index 54ae8b3e44d2eb02af7749f90ad40a3cbe480ff5..9446175e19dc80f08c1aed200509c5c4d20802c4 100755
--- a/doc/README.variables
+++ b/doc/README.variables
@@ -80,8 +80,8 @@ The dial() application sets the following variables:
 
 ${DIALEDPEERNAME} Dialed peer name
 ${DIALEDPEERNUMBER} Dialed peer number
-${DIALEDTIME}   Time for the call (seconds)
-${ANSWEREDTIME} Time from dial to answer (seconds)
+${DIALEDTIME}   Total time for the call in seconds (Network time).
+${ANSWEREDTIME} Time from answer to end of call in seconds (Billable time).
 ${DIALSTATUS}   Status of the call, one of:
                 CHANUNAVAIL | CONGESTION | BUSY | NOANSWER | ANSWER | CANCEL