Why can't I, as a host, reschedule bookings

Hosts are not able to reschedule bookings. In an emergency they can cancel, and the guest can rebook.

It is much easier for a guest to know when they can come again if they can’t make their original time slot. You can always send them the rescheduling How to from the support files to help them with this option.

Example text:

Hi (guest), You can reschedule your booking in your account to a more suitable time if needed. You can find the reschedule option next to the current booking in your bookings tab. To find out more please head here