I was checking the 'timezone' column of the 'mdl_user' table on an old Moodle site, and found the following values:
The first two are valid formats supported by PHP: http://php.net/manual/en/timezones.php. All new values get saved to that format.
Also I was able to find out that Moodle uses "99" internally to signify the server's default timezone.
Can someone however tell, what the values "1.0" and "2.0" are, and how they've ended up in the table? (There are LOTS of them.)
I'm using Moodle 3.1.6.