Score:1

Ubuntu

How can I change the timezone in which a cron job is executed?

nicholas

4/3/23, 1:01 PM

I want to change the timezone in which the cron jobs are executed but keep the rest of the system's default timezone. Is this possible?

I read this article https://linuxhint.com/set-timezone-crontab/

but I think this doesn't affect when the job is executed. It just specifies which timezone should be used by the process once launched by cron

133

0 + 0

bash

scripts

cron

20.04

waltinator

4/3/23, 1:34 PM

This sounds like an XY problem. Why can't you edit the crontab and change the times there?

nicholas

4/3/23, 1:55 PM

I can't. It's hard to give you context for that. My task is to change the cron jobs timezone.

bac0n

4/3/23, 4:21 PM

I think you can use ```CRON_TZ```. but I don't think you can change TZ on individual entries.

waltinator

4/3/23, 11:06 PM

Which do you mean? Change the time at which a `cron` job runs (edit the `crontab`) OR convince the `cron` job it's being run before a deadline (edit the `crontab`, set `TZ=` for the job)? Read `man -a crontab`.

Score:3

Ubuntu

bac0n

4/4/23, 8:00 AM

CRON_TZ instructs your cron table to run in the assigned timezone, you can also use TZ, which sets the timezone for your command if you want it to use a timezone different from the system.

# min hour dom month dow command
CRON_TZ=Europe/Helsinki
0 9 * * * TZ=Europe/Helsinki /bin/sh -c 'date +"$USER: \%a \%e \%b \%Y \%H:\%M:\%S \%Z"' >> /tmp/timestamp.log

This cron will run when the clock strikes 09:00 in Finland, i.e., 08:00 here.

[bac0n@betazoid ~ 07:59]: tail -f /tmp/timestamp.log
bac0n: Sat  4 Dec 2021 09:00:01 EET

If you want to run specific scripts in different time zones, you can use systemd.timer instead. There are endless ways to organize your timer/services, e.g., you can use an instantiated timer to add the different time zones.

# file: [email protected]
[Unit]  
Description=Timer for timezone %I  
  
[Timer]  
AccuracySec=1s  
OnCalendar=*-*-* 09:00:00 %I  
  
[Install]  
WantedBy=timers.target

The second service template is a general service for all enabled time zones, there is also possible to create a specific service for a time zone with different sets of properties.

# file: [email protected]
[Unit]
Description=Service for timezone %I

[Service]
Environment=TZ=%I
ExecStart=/bin/date +"%I: %%a %%e %%b %%Y %%H:%%M:%%S %%Z"
StandardOutput=append:/tmp/timestamp.log

Now you can start adding your time zones.

systemctl enable --now 'timezone@Europe\x2fLondon.timer' 'timezone@Europe\x2fStockholm.timer' 'timezone@Europe\x2fHelsinki.timer'

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