Once setup, BookingSync's Synchronizers will replace your portals' listing calendar by the bookings present in BookingSync. Then, any updates made into BookingSync will be synchronized with this listing to ensure that your booking calendar remain actualized.

There's some more quiet time and no bookings are made for a few days, it's then a good habit to "mark as up-to-date" your calendars. The Synchronizers will do this on the portals for you as soon as you click the button "mark as up-to-date" within BookingSync.