Dependency @vvo/tzdb does not have the right abbreviation for timezones

[stephenhmarsh]

We're currently on EDT but the Scheduler plugin says "EST" -- I think that's because its dependency @vvo/tzdb only has a single abbreviation for America/New_York as you can see here: https://github.com/vvo/tzdb/blob/158dbcf2c838aa369de0c61bfffe4e387061ea1f/raw-time-zones.json#L43

Seems there are at least a couple open issues related to this:

• Incorrect abbreviation and alternativeName? vvo/tzdb#287
• Allow multiple abbreviations / alternate names vvo/tzdb#138