Add Siem Reap (Cambodia) to your list and use my-locations table to visually convert it's time to another timezone or city time.
Mouse over the colored hour-tiles and glance at the hours selected by the column.

Current time zone for Siem Reap (Cambodia) is Asia/Phnom_Penh, whose offset is GMT+7 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Siem Reap, Cambodia is "Asia/Phnom_Penh"

It currently does not observe Daylight Savings Time.