Add Buenos Aires (Guatemala) 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 Buenos Aires (Guatemala) is CST, whose offset is GMT-6 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Buenos Aires, Guatemala is "America/Guatemala"

It currently does not observe Daylight Savings Time.