+@defun current-time-zone &optional time zone
+@cindex time zone, current
+This function returns a list describing the time zone that the user is
+in.
+
+The value has the form @code{(@var{offset} @var{abbr})}. Here
+@var{offset} is an integer giving the number of seconds ahead of Universal Time
+(east of Greenwich). A negative value means west of Greenwich. The
+second element, @var{abbr}, is a string giving an abbreviation for the
+time zone, e.g., @samp{"CST"} for China Standard Time or for
+U.S. Central Standard Time. Both elements can change when daylight
+saving time begins or ends; if the user has specified a time zone that
+does not use a seasonal time adjustment, then the value is constant
+through time.
+
+If the operating system doesn't supply all the information necessary to
+compute the value, the unknown elements of the list are @code{nil}.
+
+The argument @var{time}, if given, specifies a time value to
+analyze instead of the current time. The optional argument @var{zone}
+defaults to the current time zone rule.
+@end defun
+