Hey there @Craig35522 - great question, and thanks so much for posting!

Firstly - excellent news! Absolutely nothing will happen to your upcoming Calendly bookings if you make changes to/update your availability within Calendly! The same applies if you make updates to your connected calendar (ex. if your “check for conflicts” Google Calendar suddenly has a Google Cal event with a “busy” status added at 2pm on Tuesday and you have a Calendly booking at 2pm on Tuesday, the Calendly booking will not be impacted in any way!). 

All you need to do is update your Availability Schedules within Calendly and/or update the “custom hours” you’ve set up within specific event types, and that new availability will apply moving forward when invitees visit your booking page/s to book with you via Calendly. All previously booked times will remain under your “scheduled events > upcoming” tab in your Calendly account as they are currently booked, and they will remain as is on your connected “add to” calendar as well. 

I hope this helps!

p.s. you might wanna take a look at our New User Guide for tons of helpful info, tips & tricks as you learn the Calendly ropes! It’s super helpful. Here are a few other resources I’d want if I were new, as well: