Add Hồng Ngự (Vietnam) 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 Hồng Ngự (Vietnam) is Asia/Ho_Chi_Minh, whose offset is GMT+7 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Hồng Ngự, Vietnam is "Asia/Ho_Chi_Minh"

It currently does not observe Daylight Savings Time.