Sched. placeholder

TBA

This abbreviation often appears on event listings when details like a speaker or time are still being finalized.

Sched." is short for "schedule," so the clue is asking for a common abbreviation used as a placeholder in schedules. "TBA" stands for "to be announced," which fits perfectly as it marks an undecided or upcoming event. The clue plays on the idea of a temporary slot-holder, and "TBA" is the standard shorthand for that in calendars, TV listings, or event planning. It’s a straightforward abbreviation many people recognize from everyday use.