Rename recent calendar user option

* lisp/calendar/calendar.el (calendar-time-zone-style):
Rename from calendar-use-numeric-time-zones.
* lisp/calendar/cal-dst.el (calendar-standard-time-zone-name)
(calendar-daylight-time-zone-name):
* lisp/calendar/solar.el (sunrise-sunset, solar-equinoxes-solstices):
Use new variable name.
* doc/emacs/calendar.texi (Sunrise/Sunset): Update.
; * etc/NEWS: Update.

doc/emacs/calendar.texi

@@ -625,10 +625,9 @@ your time zone.  Emacs displays the times of sunrise and sunset
 @emph{corrected for daylight saving time}.  @xref{Daylight Saving},
 for how daylight saving time is determined.
 
-@vindex calendar-use-numeric-time-zones
+@vindex calendar-time-zone-style
   If you want to display numerical time zones (like @samp{"+0100"})
-instead of symbolic time zones (like @samp{"CET"}), set the
-@code{calendar-use-numeric-time-zones} variable to non-@code{nil}.
+instead of symbolic ones (like @samp{"CET"}), set this to @code{numeric}.
 
   As a user, you might find it convenient to set the calendar location
 variables for your usual physical location in your @file{.emacs} file.

etc/NEWS

@@ -215,15 +215,14 @@ as a data list rather than as a piece of code.
 ** Calendar
 
 +++
-*** New variable 'calendar-use-numeric-time-zones' to use numeric time zones.
-If non-nil, functions that display time zones (like the 'S' command in
-calendar mode that displays the sunrise time) will display time zones
-like "+0100" instead of "CET".
+*** New user option 'calendar-time-zone-style'.
+If 'numeric, calendar functions (eg calendar-sunrise-sunset) that display
+time zones will use a form like "+0100" instead of "CET".
 
 ** Dired
 
 +++
-*** New used option 'dired-copy-dereference'.
+*** New user option 'dired-copy-dereference'.
 If set, Dired will dereferences symbolic links when copying.  This can
 be switched off on a per-usage basis by providing 'dired-do-copy' with
 a 'C-u' prefix.

lisp/calendar/cal-dst.el

@@ -350,7 +350,7 @@ If the locale never uses daylight saving time, set this to 0."
   :group 'calendar-dst)
 
 (defcustom calendar-standard-time-zone-name
-  (if calendar-use-numeric-time-zones
+  (if (eq calendar-time-zone-style 'numeric)
       (if calendar-current-time-zone-cache
           (format-time-string
            "%z" 0 (* 60 (car calendar-current-time-zone-cache)))
@@ -360,10 +360,11 @@ If the locale never uses daylight saving time, set this to 0."
 For example, \"EST\" in New York City, \"PST\" for Los Angeles."
   :type 'string
   :version "28.1"
+  :set-after '(calendar-time-zone-style)
   :group 'calendar-dst)
 
 (defcustom calendar-daylight-time-zone-name
-  (if calendar-use-numeric-time-zones
+  (if (eq calendar-time-zone-style 'numeric)
       (if calendar-current-time-zone-cache
           (format-time-string
            "%z" 0 (* 60 (cadr calendar-current-time-zone-cache)))
@@ -373,6 +374,7 @@ For example, \"EST\" in New York City, \"PST\" for Los Angeles."
 For example, \"EDT\" in New York City, \"PDT\" for Los Angeles."
   :type 'string
   :version "28.1"
+  :set-after '(calendar-time-zone-style)
   :group 'calendar-dst)
 
 (defcustom calendar-daylight-savings-starts-time

lisp/calendar/calendar.el

@@ -1061,10 +1061,12 @@ calendar."
   :type 'boolean
   :group 'holidays)
 
-(defcustom calendar-use-numeric-time-zones nil
-  "If nil, use symbolic time zones like \"CET\" when displaying dates.
-If non-nil, use numeric time zones like \"+0100\"."
-  :type 'boolean
+;; fixme should have a :set that changes calendar-standard-time-zone-name etc.
+(defcustom calendar-time-zone-style 'symbolic
+  "Your preferred style for time zones.
+If 'numeric, use numeric time zones like \"+0100\".
+Otherwise, use symbolic time zones like \"CET\"."
+  :type '(choice (const numeric) (other symbolic))
   :version "28.1"
   :group 'calendar)
 

lisp/calendar/solar.el

@@ -840,7 +840,7 @@ This function is suitable for execution in an init file."
          (calendar-standard-time-zone-name
           (if (< arg 16) calendar-standard-time-zone-name
             (cond ((zerop calendar-time-zone)
-                   (if calendar-use-numeric-time-zones
+                   (if (eq calendar-time-zone-style 'numeric)
                        "+0100" "UTC"))
                   ((< calendar-time-zone 0)
                    (format "UTC%dmin" calendar-time-zone))
@@ -1016,7 +1016,7 @@ Requires floating point."
          (calendar-standard-time-zone-name
           (cond
            (calendar-time-zone calendar-standard-time-zone-name)
-           (calendar-use-numeric-time-zones "+0100")
+           ((eq calendar-time-zone-style 'numeric) "+0100")
            (t "UTC")))
          (calendar-daylight-savings-starts
           (if calendar-time-zone calendar-daylight-savings-starts))