What trigger conditions does the Schedule feature support? Does it support countdown timers?

The following trigger types are supported:

Trigger Type	Example
Fixed one-time	6:30 PM on a specific date
Weekly repeat	Every Monday, Wednesday, and Saturday at 6:30 PM
Monthly specific dates	20th of January, August, and December at 6:30 PM
Yearly repeat	Every January 20th at 6:30 PM
Countdown	Trigger 2 hours from now
Daylight automation (sunrise/sunset)	At sunset, or 30 minutes before sunrise

Countdown timers are supported.