Fix time-stamp-time-zone bugs introduced in July

This fixes a bug introduced when the July changes to
format-time-string installed, as the changes were not
correctly handled in this module (Bug#22302).
Also, document time stamp time zones.
* lisp/time-stamp.el (time-stamp-time-zone): Document values better.
(time-stamp--format): New private function.
(time-stamp-string, time-stamp-string-preprocess)
(time-stamp-do-number): Use it.
* doc/emacs/files.texi (Time Stamps): Mention time zones.
* doc/misc/autotype.texi (Timestamps): Document time-stamp-time-zone.

2 files changed, 9 insertions, 6 deletions

diff --git a/doc/emacs/files.texi b/doc/emacs/files.texi
index bfa55d38701..3d5562dcc47 100644
--- a/doc/emacs/files.texi
+++ b/doc/emacs/files.texi
@@ -881,9 +881,10 @@ Time-stamp: " "
 @code{before-save-hook} (@pxref{Hooks}).  When you save the file, this
 function then automatically updates the time stamp with the current
 date and time.  You can also use the command @kbd{M-x time-stamp} to
-update the time stamp manually.  For other customizations, see the
-Custom group @code{time-stamp}.  Note that the time stamp is formatted
-according to your locale setting (@pxref{Environment}).
+update the time stamp manually.  By default the time stamp is
+formatted according to your locale setting (@pxref{Environment}) and
+time zone (@pxref{Time of Day,,, elisp, The Emacs Lisp Reference
+Manual}).  For customizations, see the Custom group @code{time-stamp}.
 
 @node Reverting
 @section Reverting a Buffer
diff --git a/doc/misc/autotype.texi b/doc/misc/autotype.texi
index 839782a3b51..6bdbd344c7a 100644
--- a/doc/misc/autotype.texi
+++ b/doc/misc/autotype.texi
@@ -531,15 +531,17 @@ then @code{time-stamp} is conveniently listed as an option in the
 customization buffer.
 
 @vindex time-stamp-active
+@findex time-stamp-toggle-active
 @vindex time-stamp-format
-@vindex time-stamp-start
+@vindex time-stamp-time-zone
 The time stamp is updated only if the customizable variable
 @code{time-stamp-active} is on, which it is by default; the command
 @code{time-stamp-toggle-active} can be used to toggle it.  The format of
-the time stamp is set by the customizable variable
-@code{time-stamp-format}.
+the time stamp is set by the customizable variables
+@code{time-stamp-format} and @code{time-stamp-time-zone}.
 
 @vindex time-stamp-line-limit
+@vindex time-stamp-start
 @vindex time-stamp-end
 @vindex time-stamp-count
 @vindex time-stamp-inserts-lines