In the current version of the app, hosts are able to send an Early Check-in email, but this does not change the start and end date/time of the PIN code. We are planning to include this feature in future versions of the app.
To send an Early Check-in email to your guest:
Under Reservations menu > Select listing that is associated to the Airbnb listing > Select Reservation name > Early Check-in
An email will immediately be sent to your guest with the PIN code which starts from the indicated check-in time.
Note: This feature only allows the host to send the PIN code email earlier, but does not affect the PIN code duration.