Setting an appointment "Lead Time" is a useful tool to help you manage reservations better. The appointment "Lead Time" is the period of time before which the client can book a treatment regardless of your availability.
For example, if your "Lead Time" is set to 2 hours and a client is in the process of making a booking at 2pm, the first available appointment that they would be able to book would be at 4pm.
If the "Lead Time" is set to zero, the customer can book a treatment at the earliest available time. So, make sure that your calendar is always up to date and, this way, the customer will be able to book their treatment without any scheduling mishaps.
You can change your "Lead Time" for all services by contacting us (but bear in mind that this will impact how many customers book with you), or you can configure the "Lead Time" for individual services by clicking on the item in your menu and then heading to the "Distribution" tab.