MAG Airport Collaborative Decision Making (A-CDM) e-learning . This video describes what happens to the planned Take-Off time when the TOBT is updated.

Departure Flight Plan activation (EOBT) is 3 hours before scheduled departure. This triggers an automated TOBT (Target Off-Block Time), TTOT (Target Take-Off Time) which uses an estimated taxi-out time, and TSAT (Target Startup Approval Time) which is the time the pilot calls for startup.

If the TOBT is delayed due to a longer than planned turnaround, TTOT and TSAT can be affected.

Other acronyms in this video:
ALDT - Actual Landed Time
AIBT - Actual In-Block Time
ARDT - Aircraft Ready Time
AOBT - Actual Off-Block Time
ATOT - Actual Take-Off Time