Official deadlines should be in UTC. It is the easiest timezone for a worldwide group of players to convert. Hence, Section 1 should reference UTC. If you want to require that additional conversions be added after that for large player bases, then I would not oppose that. Those time zones should be in Section 3.

Also, if you are going to have Eastern Daylight/Standard Time could you please consider requiring it to be written as "(North American) Eastern Daylight/Standard Time" or something similar? Other places have their own Eastern Daylight/Standard Times, though all with the country or region included in the name. While players from those regions should think it odd that there is no placename in the timezone, it could be prone to people not thinking and making mistakes (which is exactly what your proposal seeks to prevent).