The tz database, also called tzdata, the zoneinfo database or IANA (Internet 
Assigned Numbers Authority) time zone database, is a collaborative compilation 
of information about the world's time zones, primarily intended for use with 
computer programs and operating systems. It is sometimes called the Olson 
database, referring to the founding contributor, Arthur David Olson. Paul Eggert 
is currently its editor and maintainer.

AmigaOS now has its own version with full support for all time zones. So far 
only Classic Amiga OS is supported but support for at least AROS is planned. 
AmigaOS 4 might already have support for this database. I haven't been able to 
find any information about it online. Read more about the database at Wikipedia 
or IANA. The primary usage is to keep your Amiga clock synced regardless of 
changes in summer and winter time. Other application might also benefit from the 
database, f.x. network time synchronization software. The software also include 
small tools, one of them being able to show the time in other parts of the 
world.

The Amiga Time Zone Database is steadily hardening. Hopefully version 5 can be 
promoted to stable. All code and data are open sourced. To get the most out of 
The Time Zone Database a RTC module is required. Are you a developer or maybe 
just a curious Amiga user, then you can download The Amiga Time Zone Database 
from aminet.