Function: set-time-zone-rule

set-time-zone-rule is a function defined in timefns.c.

Signature

(set-time-zone-rule TZ)

Documentation

Set the Emacs local time zone using TZ, a string specifying a time zone rule.

If TZ is nil or wall, use system wall clock time; this differs from the usual Emacs convention where nil means current local time. If TZ is t, use Universal Time. If TZ is a list (as from current-time-zone) or an integer (as from decode-time), use the specified time zone without consideration for daylight saving time.

Instead of calling this function, you typically want something else. To temporarily use a different time zone rule for just one invocation of decode-time, encode-time, or format-time-string, pass the function a ZONE argument. To change local time consistently throughout Emacs, call (setenv "TZ" TZ): this changes both the environment of the Emacs process and the variable process-environment, whereas set-time-zone-rule affects only the former.

Probably introduced at or before Emacs version 26.1.

Source Code

// Defined in /usr/src/emacs/src/timefns.c
{
  tzlookup (NILP (tz) ? Qwall : tz, true);
  return Qnil;
}