I live in the eastern United States.
It's Eastern Daylight Time (EDT) from the second Sunday in March to the first Sunday in November.
It's Eastern Standard Time (EST) from the first Sunday in November to the second Sunday in March.
Collectively they are America\New_York.
Thus if you're saving a DateTime with timezone to a database (perhaps Postgres) you should use America\New_York.
By doing so, you're utilizing the wonderful work done in the tz database!
Cheers.