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wiki:time_zone [2012/11/27 17:36] – add "tz=UTC+5:30"(a more standard form) bohrshaw | wiki:time_zone [2022/09/21 17:10] (current) – external edit 127.0.0.1 | ||
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+ | ====== Time Zone ====== | ||
+ | I'd just like to expand a bit on the use of the ' | ||
+ | |||
+ | ==== Without Daylight Saving ==== | ||
+ | |||
+ | In the case of no daylight saving the boot code simply needs the name of the timezone and the offset to UTC. Example India: | ||
+ | tz=IST-5: | ||
+ | |||
+ | ==== With Daylight Saving ==== | ||
+ | |||
+ | Things get a bit more varied with daylight saving. The TZ definition now also adds the name of the timezone during daylight saving and the details when daylight saving starts and ends. Example France: | ||
+ | |||
+ | tz=CET-1CEST, | ||
+ | | ||
+ | -1 | ||
+ | CEST | ||
+ | 3 start of daylight saving: the month (i.e. March) | ||
+ | 5 the week (i.e. last) | ||
+ | 0 the day (i.e. Sunday) | ||
+ | | ||
+ | 5 the week (i.e. last) | ||
+ | 0 the day (i.e. Sunday) | ||
+ | 3 the time (i.e. 03:00:00) | ||
+ | |||
+ | Please note: Since no time is specified for the start of CEST the default value of 02:00:00 will be used. | ||
+ | |||
+ | I hope this breakdown makes it easier to understand the specification mentioned above. It's actually less intimidating once you got the general idea. | ||
+ | |||
+ | If your are still not keen to create your very own TZ string you can cheat by taking a peek in the (binary) zoneinfo files of the tzdata.tcz extension. Please note that in the following steps (using London as an example) the extension gets merely downloaded (to the home directory), extracted and right away removed again. So nothing remains afterwards. Let's face it, you probably need to find out your local TZ definition only a few times in your life (e.g. when you move or your daylight saving timeframe changes): | ||
+ | |||
+ | < | ||
+ | tc@box:~$ mkdir ext | ||
+ | tc@box:~$ sudo mount tzdata.tcz ext -t squashfs -o loop, | ||
+ | tc@box:~$ find ext/ | ||
+ | GMT0BST, | ||
+ | tc@box:~$ umount ext | ||
+ | tc@box:~$ rm -rf ext tzdata.tcz</ | ||
+ | |||
+ | If you are not sure about the city to specify in the ' | ||
+ | |||
+ | From: http:// |