Check-in time is the earliest hour you may take your room. A check-in time of three, before check-in time.
It exists because the room has to be cleaned after the last guest, which is the whole reason for the gap. Most hotels will hold luggage before check-in time even if the room is not ready.
1nouncheck-in timeThe earliest hour you may take your room.
“They arrived four hours before check-in time and sat in the bar.”
check-in time is a time.
Practised in Hotel & Staying Away