Firstly, there’s only one PTR server, and it’s hosted in the Pacific Time Zone. Blizzard tend to patch the PTR server in the mid to late afternoon, in that time zone.
For players in Europe, that means the PTR won’t be available until late Thursday night or early Friday morning
For players in Asia / Australia, that means the PTR won’t be available until Friday morning, possibly afternoon.
Some examples times…
PST = Pacific Standard Time (UTC-8)
GMT = Grenwhich Mean Time (UTC+0)
CET = Central European Time (UTC+1)
AEST = Australian East Standard Time (UTC+10)
| PST | GMT / UTC | CET | AEST |
|---|---|---|---|
| 13:00 Thursday | 21:00 Thursday | 22:00 Thursday | 07:00 Friday |
| 14:00 Thursday | 22:00 Thursday | 23:00 Thursday | 08:00 Friday |
| 15:00 Thursday | 23:00 Thursday | 00:00 Friday | 09:00 Friday |
| 16:00 Thursday | 00:00 Friday | 01:00 Friday | 10:00 Friday |
| 17:00 Thursday | 01:00 Friday | 02:00 Friday | 11:00 Friday |
| 18:00 Thursday | 02:00 Friday | 03:00 Friday | 12:00 Friday |
You might also find these useful…
https://www.worldtimebuddy.com/pst-to-gmt-converter
https://www.worldtimebuddy.com/pst-to-cet-converter
https://www.worldtimebuddy.com/pst-to-aest-converter