How do I create a new availability set?

While creating or editing a Bookable Schedule, if you modify your availability and click Save Changes or Continue, you will be prompted to either update the existing availability set and all existing schedules with it or create a new set for just that schedule to potentially reuse on other schedules.

To create a new set, simply click Save as new... and name your availability set. Your changes will then be saved to the new availability set and your existing set will remain unaltered.