Add MDT (Mountain Daylight Time (North America)) 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 MDT (Mountain Daylight Time (North America)) is MDT, whose offset is GMT-6 from Greenwich Mean Time (GMT).

The IANA timezone identifier for MDT, Mountain Daylight Time (North America) is "MDT"