What is the term used for when someone says they'll show up to an event?
The closest word I can think of is RSVP.
What is the term used for when someone says they'll show up to an event?
The closest word I can think of is RSVP.
This link confirmation of attendance confirms the term.
reply to RSVP is another.
RSVP is the request to reply/confirm, but I've seen "they sent back their RSVPs" which is decidedly informal though.
The term you're looking for, I suspect, is "estimated time of arrival" or "ETA," which refers to the approximate time when someone plans to show up at a specified event.