BusyCal has recently become slow and sluggish. How can I speed it up?

The major cause of slowdowns in BusyCal is too many long-running repeating events.

If you have repeating events that have more than 200 occurrences, you should split them into multiple events of about 200 occurrences each.

To find all your repeating events, do the following:

1. switch to the List view
2. set a date range of 1 year
3. show the Repeats column and sort by it

To break long-running repeating events into multiple events do the follow:

1. select the event
2. choose Cut from the Edit menu
3. when prompted, click the Cut Future button
4. choose Paste from the Edit menu