Quote Originally Posted by HaraldGPS View Post
Is this unique to specific Garmin models? Or can I view in Nuvi250, Oregon, MobilePC? Do I have to rename it to Gmapsupp..
No, as said in this thread,in case of TimeZoneMap_900.rgn it is enough to drag this file in webupdater.exe on desktop, having you device USB attached and it will be installed.
Correct name in gps is GMAPTZ.img and it sets your timezone in your device. It is present in every gps, I guess