Add Portmore (Jamaica) 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 Portmore (Jamaica) is EST, whose offset is GMT-5 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Portmore, Jamaica is "America/Jamaica"

It currently does not observe Daylight Savings Time.