How to determine when daylight saving time changes

When you're not sure when daylight saving time changes you can quickly check it using the zdump command which is available on every *nix system.

To check this year's daylight saving time changes for Europe/Warsaw time zone execute command:

$ zdump -v Europe/Warsaw | grep 2012
Europe/Warsaw  Sun Mar 25 00:59:59 2012 UTC = Sun Mar 25 01:59:59 2012 CET  isdst=0 gmtoff=3600
Europe/Warsaw  Sun Mar 25 01:00:00 2012 UTC = Sun Mar 25 03:00:00 2012 CEST isdst=1 gmtoff=7200
Europe/Warsaw  Sun Oct 28 00:59:59 2012 UTC = Sun Oct 28 02:59:59 2012 CEST isdst=1 gmtoff=7200
Europe/Warsaw  Sun Oct 28 01:00:00 2012 UTC = Sun Oct 28 02:00:00 2012 CET  isdst=0 gmtoff=3600

As you can see for Europe/Warsaw time zone - the clock moves forward one hour to Central European Summer Time on 25 March 2012 (2:00 → 3.00 local time) and goes back one hour to Central European Time on 28 October 2012 (3:00 → 2:00 local time).

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About Milosz Galazka

Milosz is a Linux Foundation Certified Engineer working for a successful Polish company as a system administrator and a long time supporter of Free Software Foundation and Debian operating system. He is also open for new opportunities and challenges.

Gdansk, Poland https://sleeplessbeastie.eu