The more successful an executive comes in their role, the more responsibility falls on their plate. As much as you may want to do all or the majority of the work that comes your way, using your EA to schedule can help you stay on top of everybody and every project that comes across your desk.
In this role, your executive assistant takes on the role of a traditional assistant, managing time slots, and doing whatever is necessary when things come up.
Time engineering requires detailed, precise scheduling, and using their superpower of ESP, they can log pertinent information on your calendar invites or in an email you want to link a calendar invitation to.