Add Tonga (Tuvalu) 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 Tonga (Tuvalu) is Pacific/Funafuti, whose offset is GMT+12 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Tonga, Tuvalu is "Pacific/Funafuti"

It currently does not observe Daylight Savings Time.