Setting a timezone

[mmkw43]

Is there any way to set a timezone from within a python script? Naively I tried a subprocess call to raspi-config thinking it might display but the script crashed.

Is there any way to do this? BIG THANKS.

I'm wanting to do it in a preliminary tkinter with button window that pops up before the actual program starts. "Set time zone first then click button to continue".

[DougieLawson]

You shouldn't EVER need to change the system timezone after you've set it at first boot up. Leave it set to the zone where your machine is located or set it to UTC and leave it there. That's done with sudo dkpg-reconfigure tzdata. The tzdata stuff even works for daylight saving if you're in a territory that uses DST.

To deal with timezones in python use the python3 pytz package (which needs tzdata to be installed).

https://pypi.org/project/pytz/

[mmkw43]

Many thanks Doug. Yeah, I may have users in different time zones. I'll study that info. -- thanks again.

[billintad]

Python version 3.9 has improved timezone processing.

Unfortunately this version of Python is not the one loaded when you use 'python3'. I am not sure when RpiOS will offer python3.9 but it can be downloaded and compiled. I followed these instructions :

https://raspberrypi.stackexchange.com/q ... 3-7-to-3-8

but used 3.9 instead of 3.8.0. It takes a while but works.

[DougieLawson]

Python version 3.9 has improved timezone processing.

Unfortunately this version of Python is not the one loaded when you use 'python3'. I am not sure when RpiOS will offer python3.9 but it can be downloaded and compiled. I followed these instructions :

https://raspberrypi.stackexchange.com/q ... 3-7-to-3-8

but used 3.9 instead of 3.8.0. It takes a while but works.

It can't be any worse than it is now, because it's stupidly broken.

The standard RaspiOS (and DebIan) version of python won't change before Buster is replaced by Bullseye in the Autumn of 2021.

[mmkw43]

Just one simple thing I need to understand before I proceed as this is new territory.

When I'm using Python with Raspian and I manipulate the time zone setting through my code, does it overwrite (permanently) how I set up time with raspi-config? May sound like a dumb question but stranger things have happened,

I just also saw timedatectl. Saw a "set time zone" command with that. Haven't tried anything yet though, will jump into it tomorrow.

Thanks for the help.

[billintad]

...

The standard RaspiOS (and DebIan) version of python won't change before Buster is replaced by Bullseye in the Autumn of 2021.

Installing new versions of Python is described in this recent thread :

viewtopic.php?f=32&t=291158

Dealing with the continual upgrades to Python is something to be sorted out. Waiting for autumn 2021 before an upgrade will mean many useful improvements to Python will be missing from RaspiOS, for example 3.10 will bring an improvement in speed of 10%, with the aim to improve processing speed by 50% over the next few releases. Any discussion of this probably needs a separate thread, but the issue does need to be addressed.

[DougieLawson]

Don't blame me, go and moan at the less than agile folks who maintain DebIan.

The conservative approach to new versions and releases with DebIan is one reason to switch to Ubuntu (which has a more modern approach but more frequent package upgrades).

[fruitoftheloom]

...

The standard RaspiOS (and DebIan) version of python won't change before Buster is replaced by Bullseye in the Autumn of 2021.

Installing new versions of Python is described in this recent thread :

viewtopic.php?f=32&t=291158

Dealing with the continual upgrades to Python is something to be sorted out. Waiting for autumn 2021 before an upgrade will mean many useful improvements to Python will be missing from RaspiOS, for example 3.10 will bring an improvement in speed of 10%, with the aim to improve processing speed by 50% over the next few releases. Any discussion of this probably needs a separate thread, but the issue does need to be addressed.

If you have a RPi 4B run Manjaro ARM64, being based on ARCH it is always latest and greatest packages:

https://manjaro.org/downloads/arm/raspb ... pi-4-xfce/

[DougieLawson]

If you have a RPi 4B run Manjaro ARM64, being based on ARCH it is always latest and greatest packages:

https://manjaro.org/downloads/arm/raspb ... pi-4-xfce/

I've never tried Manjaro; is that Arch with a easy to get configured GUI? Plain old Arch isn't good for folks who've not had years of experience with Linux. I tend to like Ubuntu and Mint because they're in the familiar territory of apt, apt-get, synaptic and aptitude for package management.

[bls]

OP: Just a thought...If you explained what you are trying to accomplish overall, instead of the point "how do I change the timezone in Python and how does this affect the system" questions, you might get additional helpful responses.

[mmkw43]

I'm simply trying to allow a user (who can live anywhere in the US) to change the timezone. Guess I didn't communicate that.
Using PI3 and Jessie and python3.4 -- and did this,

pip install pytz (tzdata was already installed).

It installed but I can't even get this done in python --

import pytz
for timezone in pytz.all_timezones:
print(timezone)

says pytz has no attribute all_timezones -- I verified that it DOES.

[mmkw43]

Spent all day on it to find out --

timedatectl set-timezone "America/City"

pretty god damn easy.
I'm not pro like you guys -- just a hobbyist. looking for simple answers.

[DougieLawson]

Spent all day on it to find out --

timedatectl set-timezone "America/City"

pretty god damn easy.
I'm not pro like you guys -- just a hobbyist. looking for simple answers.

That's what sudo raspi-config does for you. I think we'd assumed you'd set the system timezone right before starting your python struggle. That setting you've changed is for every user and every process.

[bls]

I think we'd assumed you'd set the system timezone right before starting your python struggle.

This is precisely why I asked the question. The correct way is to have the timezone set as part of bringing up the system at each location.

There are many ways to do this, of course. One approach is to build the SD Cards for each site with the correct timezone in them. If the OP used my sdm tool (see sig), he could still have a single master image, yet generate SD cards for each location with the correct timezone.