“Warning Message” keep showing at backend (timezone related)

Using a UTC offset timezone like “UTC+8” is not recommended, because PHP can’t accurately calculate any adjustments such as Daylight Saving Time. You should use a city-based timezone, for the city closest to your location in the same timezone, e.g. Asia/Beijing.

Dear Author,

Thank you so much for the explanation!

After I switch to the city, the warning message no longer appears!!

Maybe my country – Malaysia have no “Daylight Saving Time” as we don’t have 4 seasons, so I’m not aware of city-based timezone previously ??

That makes sense… I wasn’t sure where you were located, but that’s the tricky thing with these UTC offset timezones. Some cities in the same timezone do or don’t use Daylight Saving Time, so they end up being in the same timezone for only part of the year. So we have this elaborate list of cities instead, based on all of the various local rules that may not always adhere to strict UTC offsets.

Because PHP is so heavily centered around the city names, some of the date and time functions don’t always return reliable results for UTC offsets, even if you’re in a place with no special rules… hence everyone ends up having to use the city names.