Adjustments of data or timeslots for active bookings are not possible as soon as the rental period starts. Is the renter aiming at picking the car up earlier than the agreed time? In that case the renter can make an additional rental request for the timeslots before the confirmed booking. Renters can also request an extension of the rental period. This can be done up to one hour before the booking ends. The extension is confirmed as soon as you accept the request and the renter pays for it. You will be able to see the rental extension in your SnappCar profile.