I was wondering, the publicly announced departure time of a commercial flight, is it the ETOT (estimated takeoff time) or is it the EOBT (estimated off-block time)? Or maybe some other time?
The scheduled time is the EOBT. Flights that depart within 15 minutes of it are considered on-time. Standard taxi times for each airport are included in the scheduled flight time.
In this document you will find some of the many timestamps used in CDM. As you can see there, the EOBT is the timestamp displayed in the flight plan.
The time on the ticket usually corresponds to the ETA/ETD which in term should be STOT (scheduled take-off time).
Are you extracting information from a data source or are you just curious?