Hi, @MichaelWeiss, did you import the Scoutbook calendar to the Google calendar, or link it? Or was it the other way around (imported a Google calendar to Scoutbook)? If it’s imported either direction, I think you’re stuck deleting each individual item as @RickBerg wrote . If it’s linked, I think the suggestion below might work for subunits, but I’m not sure how you would do it for a unit calendar.
If it is a subunit (patrol) calendar, you could temporarily move all of the scouts to a “holding” patrol, then delete the existing patrol (which I think will delete the associated calendar, including past events if they exist). Then, you should be able to create a new calendar and rename the “holding” patrol to the real patrol name. You would need to link the “new” Scoutbook calendar to the Google calendar with a new ics link.