A matter of time

Pedroski · 11-16-2021, 06:09 PM

I am used to using shared webhosts.

They usually have the server time on UTC, which is 8 hours behind my time here in China.

So when I set timers with PHP, I always need to subtract 28800 seconds to get the right time on the server.

Now I am trying to use a cloud server, which is located in Chengdu, China, I believe.

The server is on normal Chinese time, not UTC.

Will this affect anything in anyway??

michaelk · 11-16-2021, 06:58 PM

Maybe, The system clock is always UTC. The default time that is displayed via the date command is whatever timezone is configured.

What default timezone PHP uses is defined in the php.ini file date.timezone configuration setting. If you can not modify the php.ini file you can set the time zone in your actual php script using the date_default_timezone_set function.

dugan · 11-16-2021, 08:42 PM

If you were converting times away from UTC and storing the "corrected" values, then yes you're in trouble. I remember explicitly telling you not to do that.

frankbell · 11-16-2021, 08:51 PM

You might want to take a look at the timedatectl command. It's output may cast some light on the situation.

I think it's a systemd-related command, as I had not heard of it until this thread caught my interest, but the odds are pretty good that your shared host uses systemd.

Pedroski · 11-17-2021, 01:10 AM

Thanks for your replies.

I wasn't complaining in any way.

I am quite happy to have the server time on Chinese normal time, saves me arithmetic, which I am not good at!

I didn't set or unset anything, that's how the Ubuntu server installation was when I got it.

I just wondered it there could be any negative consequences at all.

pan64 · 11-17-2021, 02:01 AM

Quote:

Originally Posted by Pedroski

I just wondered it there could be any negative consequences at all.

That is actually depends on the software you use. If those can handle it properly. (I don't mean perl, php, python or whatever tools themselves, but the code running ....)

michaelk · 11-17-2021, 05:19 AM

Usually the default timezone in the php.ini file is left blank blank which defaults to the timezone of the server. Since that is what you want there isn't a problem.

From personal experience I always get a postgresql warning that I should specifically set the timezone and not leave it a default.

ondoho · 11-18-2021, 12:58 AM

Quote:

Originally Posted by Pedroski

I am quite happy to have the server time on Chinese normal time, saves me arithmetic, which I am not good at!

That's what correctly setting up your system's (and PHP's) locale is there for!

sundialsvcs · 11-18-2021, 08:51 AM

Typically, everyone sets their server hardware clocks to UTC. Then, they set the time-zone according to where the server is located. This gives them binary clock-values that are directly comparable anywhere in the world, while offering time displays that are correct for the location. It's very unusual that a Chinese server operator would set the hardware clock to local time.

michaelk · 11-18-2021, 09:09 AM

I think I know what you were try to write but the hardware clock and system clock are technically independent of each other. The system clock is always UTC but would say that most set a server's timezone to UTC versus local time.