Add Gary Island (Grenada) 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 Gary Island (Grenada) is AST, whose offset is GMT-4 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Gary Island, Grenada is "America/Grenada"

It currently does not observe Daylight Savings Time.