从GMT时间和用户时区计算时间

Question

I have one mysql DB saving time for every record with GMT time for every user. like

id user_id   date_added
1  1        2016-06-08 12:22:19
2  2        2016-06-08 11:22:14
3  4        2016-06-08 11:02:09
4  1        2016-06-08 10:12:11

I also have table saved timezone for each user like

id  user_name   timezone
1   user1       Pacific/Midway
2   user2       Asia/Dubai

now i want to calculate real time for user record using above time zone in PHP.

i tried many examples but not working cause some zone are + and some are -

Thanks

Answer 1

Assuming that all dates are stored in UTC date format, you need to convert the timezone to get the local time for each user.

Example:

// default timezone is UTC
$date = new DateTime('2016-06-08 12:22:19', new DateTimeZone('UTC'));
var_dump($date->format('Y-m-d H:i:sP'));

// convert timezone to Asia/Dubai +4 UTC
$date->setTimezone(new DateTimeZone('Asia/Dubai'));
var_dump($date->format('Y-m-d H:i:sP'));

The output will be

   string '2016-06-08 12:22:19+00:00' (length=25) 
   string '2016-06-08 16:22:19+04:00' (length=25)

To get rid of +00 and +04 change the format by removing P

$date->format('Y-m-d H:i:s')