AWS Elemental MediaLive
User Guide

Deleting Actions in the Schedule

You can delete actions that you previously created in the schedule. The action you are deleting must have a UTC start time or a follow start time (for input switches) that is at least 15 seconds in the future. (In other words, it must not be already received in the channel.) After that cutoff, the delete request will be rejected.

You can delete an action from the schedule when the channel is running or when it isn't running.