Simple rule
Use ET in invites unless the exact standard-vs-daylight distinction matters.
EST is Eastern Standard Time. EDT is Eastern Daylight Time. Same region. Different part of the year. That is the whole game.
If you want fewer scheduling mistakes, use ET when you mean the general Eastern Time zone and use EST only when you really mean standard time.
| Term | Meaning | When it applies |
|---|---|---|
| EST | Eastern Standard Time | Winter months in places like New York |
| EDT | Eastern Daylight Time | Spring to fall when DST is active |
| Safer label | ET | When you want a general label without forcing people to think about DST |
Use ET in invites unless the exact standard-vs-daylight distinction matters.
If someone writes EST in July, pause and confirm the city and date.
For product data and APIs, use an IANA timezone like America/New_York instead.