There is no cut-off time. You can schedule a route weeks out or ask for a pickup as soon as possible.
Booking early still pays off. The earlier your route goes up, the more drivers see it, and the better your chances of getting one of your preferred drivers.
For most vehicle types, give it at least 24 hours.
You can still change a booked delivery after a driver takes it. Add stops, remove stops or edit the details until the driver completes the first stop on the route. Once a driver is assigned, changes to the time, the location or the delivery requirements need the driver to confirm.