The phrase "meeting slot" is correct and usable in written English. You can use it to refer to a scheduled meeting time, or a time slot that has been set aside for a meeting or appointment. For example, "I have a meeting slot at 10:00 AM tomorrow.".

What are Time-Slot Intervals. Time-Slot Intervals dictate the frequency of available appointment slots to the client when booking. For example, if you set an interval of 30 minutes, your online calendar will display available time slots for the service beginning at each half-hour of the day.