Early check-in and late checkout are requests to occupy the room before the standard check-in time or after the standard checkout time. When the room is free they are easy wins for guest satisfaction, and they can also be sold as paid add-ons, which makes them a source of ancillary revenue.
The constraint is operational: an early check-in needs a room already cleaned, and a late checkout delays housekeeping for that room and possibly the next arrival.
In practice: set a clear rule (a fixed fee, or a share of the nightly rate, with a cut-off time beyond which it becomes a day-use or an extra night) and check the room grid and housekeeping plan before promising anything. If the room has a same-day arrival, the answer has to be no.
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