Lead Time is one of the features you can set for each service. You can think of “Lead Time” as “Advanced Notice to be booked”.
An example: Let’s say I have availability every day, but my Lead Time is set to 3 days. If today is Tuesday morning, the soonest someone would be able to book me is Friday morning. This means that any available slots you have within those 3 days won’t be shown as an option for them to book.