Free Slots Between Meetings

For one day's meetings, return the gaps between consecutive meetings as free_start and free_end, ordered by free_start. Ignore gaps of length zero.

Table schema

Meetings(id INT PRIMARY KEY, start_time TIME, end_time TIME)

Sample data

id | start_time | end_time
1 | 09:00 | 10:00
2 | 10:30 | 11:00
3 | 13:00 | 14:00