TIMEZONE(3) Library Functions Manual TIMEZONE(3)

timezonereturn the timezone abbreviation

Standard C Library (libc, -lc)

char *
timezone(int zone, int dst);

This interface is for compatibility only; it is impossible to reliably map timezone's arguments to a time zone abbreviation. See ctime(3).

The () function returns a pointer to a time zone abbreviation for the specified zone and dst values. The zone argument is the number of minutes west of GMT and dst is non-zero if daylight savings time is in effect.

ctime(3)

A timezone() function appeared in Version 7 AT&T UNIX.

April 19, 1994 macOS 15.2