31422: better heuristic for timestamps in age function

ChangeLog

@@ -1,3 +1,8 @@
+2013-05-29  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+
+	* 31422: Doc/Zsh/calsys.yo, Functions/Calendar/age: better
+	heuristic for timestamps in use of :file feature.
+
 2013-05-22  Peter Stephenson  <p.w.stephenson@ntlworld.com>
 
 	* 31405: Doc/Zsh/options.yo: weasel words about

Doc/Zsh/calsys.yo

@@ -665,10 +665,15 @@ Instead of an explicit date and time, it's possible to use the
 modification time of a file as the date and time for either argument
 by introducing the file name with a colon:
 
+example(print *+LPAR()e-age :file1-+RPAR())
+
+matches all files created on the same day (24 hours starting from
+midnight) as tt(file1).
+
 example(print *+LPAR()e-age :file1 :file2-+RPAR())
 
-This matches all files modified no earlier than tt(file1) and
-no later than tt(file2).
+matches all files modified no earlier than tt(file1) and
+no later than tt(file2); precision here is to the nearest second.
 
 texinode(Calendar Styles)(Calendar Utility Functions)(Calendar System User Functions)(Calendar Function System)
 sect(Styles)

Functions/Calendar/age

@@ -33,6 +33,7 @@ zmodload -i zsh/parameter
 
 autoload -Uz calendar_scandate
 
+local timefmt
 local -a vals tmp
 
 [[ -e $REPLY ]] || return 1
@@ -40,14 +41,19 @@ zstat -A vals +mtime -- $REPLY || return 1
 
 if (( $# >= 1 )); then
   if [[ $1 = :* ]]; then
-    zstat -A tmp -F "%Y/%m/%d" +mtime -- ${1#:} || return 1
+      if (( $# > 1 )); then
+	  timefmt="%Y/%m/%d:%H:%M:%S"
+      else
+	  timefmt="%Y/%m/%d"
+      fi
+      zstat -A tmp -F $timefmt +mtime -- ${1#:} || return 1
     local AGEREF=$tmp[1]
   else
     local AGEREF=$1
   fi
   # if 1 argument given, never use globally defined AGEREF2
   if [[ $2 = :* ]]; then
-    zstat -A tmp -F "%Y/%m/%d" +mtime -- ${2#:} || return 1
+    zstat -A tmp -F "%Y/%m/%d:%H:%M:%S" +mtime -- ${2#:} || return 1
     local AGEREF2=$tmp[1]
   else
     local AGEREF2=$2