Unix and Linux Stack Exchange
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Questions tagged [timezone]

When using or applying a TZ value.

Each place on earth has a local time, that local time is set by the value of the timezone used relative to the Zero time (UTC). There are more than 500 localtimes (zones that keep the same local time) but only about 40 Time Zones (some countries use 30 minutes offsets).

244 questions
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How can I examine the contents of /etc/localtime?

What command(s) can I use to examine the contents of the timezone files, such as /etc/localtime or the files under /usr/share/zoneinfo/*?
slm
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13
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2 answers

Why is zone.tab missing so many time zones?

There are over a thousand time zone files on your typical *nix box (in /user/share/zoneinfo). Many of them vary only in historical dates which have little relevance for programs which care only about recent dates - or even only about the current…
Jonathan M Davis
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4
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3 answers

Why is there a difference between timezone America/Chicago (CST6CDT) and Etc/GMT-6?

Here is my code: #include #include time_t my_timegm (struct tm *tm, char *tz_offset); int main (void) { struct tm time_tm; time_t start_timet, end_timet; time_tm.tm_sec = 0; time_tm.tm_min = 0; time_tm.tm_hour = 0; …
Walter L. Preuninger II
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4
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2 answers

How do I report an incorrect timezone?

Timezone information for Cayman Islands is incorrect. The Cayman Islands government toyed with the idea of changing the timezone to have daylight savings, in effect matching US/Eastern time, however this did not come to fruition. As such, when…
Steve Lorimer
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2 answers

How to fix the Brazilian daylight saving time (Summer Time) of 2018 in Olson database files?

The Brazilian Government has just issued a law that shifts the beginning of the Brazilian DST (Daylight Saving Time) locally called as Summer Time. This new DST date will come into force in the next month, to be more precise on 18th of November of…
Luciano
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3
votes
1 answer

Does it matter what state I set if both locations are in the same timezone

Is there any difference if I set the timezone to timezone: "America/New_York" verses timezone: "America/Detroit" Both States are in the same timezone but other than identifying exactly where you are in the timezone, what functionality does it…
Phill Pafford
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1 answer

timezone: how to get the rules

How can I see my current timezone rules? I found out about to set it (tzdata, zic, /etc/timezone) but not how to go the other direction. (The files in /usr/share/zoneinfo are binary and I can't read them; maybe they got compiled with zic?) How do I…
chris01
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1 answer

Where is zdump getting all these time transitions from?

I recently wrote some code to parse the binary timezone data from the Olson zoneinfo database. As far as I can tell, my code is correct and matches the spec as written in C. However, I get different results when comparing the results of my tool to…
Ben S
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1 answer

Not able to set time zone on ArchLinux

I would like to set my timezone to Asia/Kolkata. Here is the error I see on using timedatectl: $ sudo timedatectl set-timezone Asia/Kolkata Failed to set time zone: Invalid or not installed time zone 'Asia/Kolkata' And here is the output from…
babon
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1 answer

Updating Olson timezone database in a running system

Is it possible to update an Olson timezone database without stopping the current running systems? I think that the renaming of folders and files of the or inside the zoneinfo folder can't accomplish that purpose. Am I right? How can we do an update…
Luciano
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1
vote
1 answer

Timezone format in /etc/timezone of Debian 7

In my Debian 7 OS: cat /etc/timezone Asia/Shanghai In one of my friends' Debian 7 OS: cat /etc/timezone Etc/UTC Why is it not of the format of Continent/City?
showkey
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0
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1 answer

What timezone formats are there?

What timezone formats exists on UNIX systems? Can someone gather them in a short answer? How can I recognize them?
gasko peter
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0
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3 answers

How can I install the TZ database on an embedded Linux platform?

I have an embedded Linux device for which the stock operating system image does not include the TZ database files usually found in /usr/share/zoneinfo. I wish to enhance the device in order to be able to include timezone support in my application.…
Richard Lang
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difference between timezone in ssh and in php?

why i have difference between timezone in ssh and php $ TZ=Africa/Khartoum date print : Mon Apr 30 13:40:41 CAT 2018 but in php date_default_timezone_set('Africa/Khartoum'); echo date('D M d Y H:i:s'); print : Mon Apr 30 14:40:41 CAT 2018 so…
mrmelad
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Dynamic time zone in a running service

A unique service instance needs to change the timezone according to the data being processed. So, it can change the TZ environment variable for each data before its processing, and so on. What is the best approach to change the TZ value to set time…
Luciano
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