When you add an event, set Repeats to weekly, every two weeks or monthly, and choose the date the series should stop.
The series is stored as one entry, not forty copies. "Soccer every Tuesday until June" reads as one line in your record, which is what you want if anyone ever reads it.
Things worth knowing
- A 5pm event stays at 5pm through daylight saving changes, rather than drifting an hour.
- A monthly event on the 31st simply skips months that don't have one, instead of jumping to the 1st.
- Editing the event changes the whole series.