Add the ability to request a different meeting duration

[malini]

Is your feature request related to a problem? Please describe.
Your calendar is set up to accept bookings of a fixed duration, and that one duration applies to anyone booking you. It would be nice to give the user who is booking you an option to request a different duration. For example, if Melissa gives me her booking url to book her for an hour, but I only need a half hour, I'd like there to be some way that apmt.day handles that situation

Describe the solution you'd like
Good question! I'm not sure what it should look like.

Perhaps an input field like this, but label it "Propose a different duration" or the like:

On the booking confirmation page?