Say you are speaking to a customer or a friend via email, whatsapp or messenger and you want to offer them a time to catch up that is not a standard service. You want to over-ride your working hours, durations etc. As of April 2019 you can!
Navigate to your appointments screen > new adhoc meeting > select some starting times from the left side of the screen > select how many people you want to share your link with (note: no concurrent/group bookings are available as yet) > create a name for your service > set a duration > generate link > share it
Video instructions below: