PHP: Why won't timezone_name_from_abbr works with a GMT offset of 8?

Question

I'm trying to use timezone_name_from_abbr() with an offset of GMT+0800, but it doesn't return the expected timezone:

echo "timezone =" . timezone_name_from_abbr('', 8 * 60 * 60, 0) . '<br/>';

According to the documentation this is supposed to work:

If abbr doesn't exist then the time zone is searched solely by the gmtOffset and isdst.

What I am doing wrong? GMT+0800 is a valid timezone for Asia/Singapore.

Answer 1

Not a very fancy answer, but it's a bug (Bug #44780 - some time zone offsets not recognized by timezone_name_from_abbr) that has been around for quite a while.

Basically, this particular timezone (and some others) only resolve to a name when you pass an abbreviation, regardless of what the documentation says.

Btw, the return value is false in the case whereby the function can't resolve the name.