user time zone bug

Hello!

Unfortunately, $this->user->format_date does not respond correctly to all timestamps.

I created two example timestamps (2021-03-28 00:00 - 1616886000 and 2021-03-31 23:59 - 1617231540).

The

$this->user->format_date(1616886000, 'Y-m-d H: i', true);

return correct value :: 2021-03-28 00:00

The

$this->user->format_date(1617231540, 'Y-m-d H: i', true);

return incorrect value :: 2021-04-01 00:59

If I subtract the timestamps from the other 1617231540 - 1616886000 = 345540/60 = 5759 min = 3 days 23 hours and 59 minutes

2021-03-28 00:00 + 3 days 23 hours and 59 minutes = 2021-03-31 23:59

So 2021-04-01 00:59 is a really wrong value.

If use the

date('Y-m-d H: i', 1617231540 + $this->user->timezone->getOffset(new \ DateTime));

then add back display correct date 2021-03-31 23:59

So only the $this->user->format_date function is faulty.

My PHP 7.4 and phpBB 3.3.3 setting: Europe/Budapest

I would ask you to investigate this, thank you in advance.