List schedule
Every slot in this station's schedule, earliest in the day first
Create schedule slot
Adds a slot. The station does not change over until its start time comes round
Read current slot
Which slot the clock says should be on, and which one the station is actually airing
Read timetable
The station's day as blocks, contiguous and gapless, for drawing
Update schedule slot
Rewrites a slot. Takes effect at its next boundary rather than immediately
Delete schedule slot
Removes a slot. Whatever is on air stays on until the next slot begins