iCal calendar sync: why double bookings happen and how to avoid them

An iCal link is a web address that returns a calendar file. The file lists which nights are taken. It contains dates, and often little else. Calendar sync between your system and a portal uses two of these links per room, one in each direction:

• Import: the portal publishes a link for each of your rooms. You paste it into your booking system, which reads it from time to time and blocks those nights.
• Export: your booking system publishes a link for each room. You paste it into the portal as an imported calendar, and the portal blocks those nights on its side.

Nothing is pushed. Each side asks the other for the calendar on its own schedule, and only reads what is there at that moment.

Two things make the sync slow, and both are outside your control.

Portals refresh only every few hours

When you add a portal's calendar to your booking system, the portal also fetches your calendar, but it does so on its own timetable. For most portals that is every few hours, sometimes less often. Nuitina reads imported calendars about every 10 minutes, so portal bookings reach you quickly. A booking that comes in through your own website or by phone, though, only reaches the portal when the portal next reads your link.

The overlap window

Picture the last double room for a Saturday. A guest books it directly on your website at 10:00. The portal does not read your calendar until 13:00, so until then it still shows the room as free. Another guest books it there at 11:30. Both bookings are valid, and you now have one room and two guests. The time between the first booking and the next calendar read is the overlap window. It is short, but it is real, and it matters most when you have only one room of a kind left, or when you are nearly full.

Set it up per room, in both directions

A one-way sync is a double booking waiting to happen. For every room that is sold on a portal, import the portal's calendar into Nuitina and paste the room's export link into the portal. Do it for every room, not just the popular ones. In Nuitina this is under Settings → Channels. The export link is secret and contains occupancy only, no guest names.

Close the last room quickly

When you are down to the last room for a date, do not wait for the sync. Close that date by hand on the other portals. If the overlap window is dangerous anywhere, it is on the last room.

Check the overlap warning

Make the dashboard a morning habit. The Today screen shows overlaps between your bookings and a channel calendar, and in the Channels settings you can use Read now to fetch the portal calendars at once. If you find an overlap, act on it the same day: contact the guest who booked last, offer another room or date, and cancel through the portal's own process.

Block dates in one place only

If you close a night for repairs, do it in your booking system and let the sync carry it to the portals. Blocking in several places makes it hard to know which entry is the real one, and you can end up unblocking a night in one place while it stays blocked in another.

Use instant booking carefully

Many portals let you choose between instant confirmation and a request that you approve. Instant confirmation is convenient but risky when the sync is slow. For the last room, or for busy weekends, consider the approval mode on that portal, if it offers one.

A channel manager with a direct connection to the portals' own systems (an API connection) works differently. Bookings and changes are passed on within moments, and it can also send prices, restrictions and room descriptions to the portal. That shrinks the overlap window a lot and saves you from updating several places. It also costs more and is meant for larger houses with many rooms and lots of daily changes.

Nuitina does not have such a connection today. It syncs calendars over iCal, and only availability, not prices or descriptions. For a small house with a handful of rooms and one or two portals, iCal plus the habits above is usually enough. If you are selling through many portals, or a double booking would be very costly, a full channel manager is worth a look.