I obtained the GIF map (above) from ftp://ftp.sunet.se/pub/pictures/maps/timezone.gif on 20 September 1995. The following citation record appeared with the map in file timezone.txt:
Newsgroups: alt.binaries.pictures From: clafave@iat.holonet.net (Christopher R LaFave) Subject: GIF of world's time zones (1/1) Organization: HoloNet National Internet Access System: 510-704-1058/modem Date: Wed, 13 Jul 1994 06:01:43 GMT