Hey there @Sara14609 - great question!
At this time there is no way to make this happen within a single event type, in automated fashion. If you offer multiple location options on an event type those will be available for invitees to choose from on all dates/times. That said, there’s a way to work this out!
You can create two event types - one with a virtual location and one with an in-person location - and set them up with different availability as appropriate. Then, you can use routing to allow invitees to be sent to the event type that makes sense for them in a more seamless fashion. Routing forms let you request information such as industry, company size, specific interests, etc. from website visitors and automatically direct them to a specific scheduling or web page based on their responses. It's great for screening and qualifying sales leads on a website or matching clients or students to the booking page of the right subject-matter expert based on their interests, program, or other criteria. You can read more about setting up routing forms, here!
In your use case, for example, you could ask a question like, “Do you prefer to meet in person or virtually?” and have the invitee routed to the event type that aligns with their response. If there are not any upcoming opening on your in-person event’s availability you can also set it up so they are shown a custom message telling them to try again later (for example).
Even if you do not prefer to set up routing, however, the two event types solution should do the trick! Simply make sure to mark yourself as unavailable for the desired dates on the “in-person” event and available on the desired dates for the “virtual” event and then let invitees book!
Be sure to also check out our New User Guide - it’s a great resource as you get started with Calendly! I’ll share some community articles that you might like, too!
I hope this helps! Let me know if you get stuck on anything - or just curious!