Connecting an outside calendar to a Space

Plenty of the commitments on a room, or on a person, never start life in 1pm. A hotel's ballroom is also booked through the group sales system. A restaurant's private dining room carries a standing Tuesday supper club that lives in a Google calendar. A photographer has a day blocked out in Apple Calendar for a school pickup, a holiday, or a shoot booked before they moved to 1pm.

Connected calendars lets a Space show those times. You paste in the calendar's private link, 1pm reads it every 20 minutes, and the Space lists the upcoming times that calendar says it is busy. It is a read-only view: 1pm never writes to the calendar, and it never creates bookings, leads or appointments from it.

What it does and does not do

It helps to be clear about this before you connect anything.

It shows busy times on the Space and on the calendar. Open the Space and you see the next dozen times the connected calendars are busy, so you can check a date before you quote it. The same times show on the calendar as grey Busy chips, alongside your bookings.
It shows when, never what. 1pm keeps the start and end of each entry and throws the title away. "Dentist, 2pm" arrives as "Tue 14 Oct 14:00-15:00, Busy". Nothing about what the entry was, who it was with, or where, is stored.
It can close appointment slots, if you turn that on. Each connected calendar has a Close appointment slots when this calendar is busy setting. With it on, clients cannot book an appointment on your booking page at a time that calendar is busy. It is off unless you turn it on. See Closing appointment slots below.
It never blocks your own bookings. A busy time from an outside calendar never stops you saving an event or adding an appointment yourself, and never raises a double-booking warning. Those checks work only from bookings and appointments inside 1pm. See Preventing a double-booked Space for how they work.
It does not import. If you want the entries in an outside calendar to become real bookings in 1pm, use Importing bookings from a calendar instead. That is a one-off upload that turns entries into events. Connected calendars is the opposite: a live view that stays in the other calendar.

Connecting a calendar

Go to Spaces and open the Space.
Find the Connected calendars card. It only appears on a Space that has been saved, so save a new Space first.
Paste the calendar's private link into Calendar link (secret iCal / ICS URL).
Add a Label if you like, such as "Ballroom in Delphi" or "My Google calendar". It is only there to tell your connected calendars apart.
Press Connect calendar.

1pm reads the calendar straight away, and the busy times appear on the card within a few seconds. Reopen the Space if they are not there yet.

A link can start with https://, http:// or webcal://. All three work, and 1pm reads a webcal:// link over a secure connection. Each calendar can be connected to a Space once: connecting the same link again tells you it is already there.

Finding the private link in your calendar

Every major calendar can publish a private address that other apps read from. It goes by a few names: iCal link, ICS link, secret address, or subscription URL. It is always a web address, never a file you download.

Google Calendar: open Settings, pick the calendar under Settings for my calendars, then scroll to Integrate calendar and copy Secret address in iCal format.
Outlook and Microsoft 365: open Settings, then Calendar, then Shared calendars. Under Publish a calendar, choose the calendar, set it to show Can view when I'm busy or more, press Publish, and copy the ICS link.
Apple iCloud Calendar: in Calendar on the web or on a Mac, share the calendar, turn on Public Calendar, and copy the link. It starts with webcal://.
Booking tools such as Acuity or Calendly, and most venue and hotel sales systems, offer a calendar feed link in their calendar or integration settings. Look for iCal, ICS or "subscribe".

Treat the link like a password. Anyone who has it can read that calendar, which is why Google calls it a secret address. If a link is ever shared somewhere it should not be, reset it in the calendar app (Google has a Reset button beside it) and connect the new one.

Which calendar to connect

Everyone on your account can see the busy times on a Space, including the team members you share your account with. Titles are never shown, but the pattern of when someone is busy still is. So connect a calendar that belongs to the Space or the business, such as a room's booking calendar or a shared studio calendar, rather than a private personal one.

A Space can have up to five connected calendars. That covers a room booked through more than one system, or a person with a work calendar and a studio calendar. Connecting the same link to the same Space twice is refused, since it would only show every busy time twice.

What counts as busy

1pm reads each entry the way the calendar itself describes it.

Timed entries show their start and end, for example "Sat 18 Oct 14:00-17:30".
All-day entries show as the whole day, and entries running across several days show their first and last day.
Repeating entries show every time they happen. A weekly Tuesday booking appears on every Tuesday. If you move one Tuesday to a Wednesday in the calendar, it shows on the Wednesday only, and a single Tuesday you cancel disappears.
Cancelled entries are left out, and so is anything the calendar marks as free (Google's Show as: Free, for example).
Your own 1pm bookings are left out. If the calendar you connect also subscribes to your 1pm calendar feed, those bookings come back through it. 1pm recognises them and skips them, so the list only shows commitments made outside 1pm.

1pm reads a year ahead, so a date you are quoting for next season is covered.

Busy times are shown in your account's time zone, the one set on Profile. 1pm reads the time zone the calendar publishes with each entry and converts it, so a meeting your calendar holds at 5pm Sydney time shows as 4pm if your account is on Brisbane time in summer. If your account has no time zone set, times are shown as the calendar wrote them, so set one on Profile if busy times look a few hours out. See time zones in 1pm.

Closing appointment slots

If clients book appointments with you through your booking page, you can stop them booking at times you are already busy somewhere else. This is how a photographer keeps consultation calls clear of shoots in their Google calendar, or a venue keeps site visits clear of the functions in its sales system.

Turn on Close appointment slots when this calendar is busy under the calendar on the Space. You can also tick it when you first connect the calendar. The booking page then leaves out every slot that overlaps a busy time from that calendar:

A timed entry closes the slots it overlaps. A meeting from 10:00 to 11:00 closes the 10:00 and 10:30 slots, and leaves 11:00 open.
An all-day entry closes every slot that day, and an entry running across several days closes every slot from its start to its end.
Your buffer applies. If the Space has a buffer between appointments, busy times get it too, just like an appointment. With a 15-minute buffer, that 10:00 to 11:00 meeting also closes a slot starting before 11:15.

The setting is per calendar, so a Space can have one calendar that closes slots (your work calendar) and another that is only there for you to look at (a partner's or a room's reference calendar). Turn it off and the busy times stay on the Space, they just stop closing slots.

Allow for the calendar's delay. 1pm reads your calendar every 20 minutes, but the calendar app decides how often it updates the private link. Google and Outlook can take up to 24 hours to publish a change there. An entry you add today for later this week closes its slots well before then, but one you add for this afternoon may not close its slot in time. For a same-day commitment, add an appointment for yourself in 1pm as well, which closes the slot straight away.

Busy times close slots in your account's time zone, the same zone the booking page shows its slots in, so the right slots close even when your calendar is set to a different zone. This needs a time zone set on Profile.

Keeping it up to date

1pm reads every connected calendar every 20 minutes. Under each calendar, the card shows when it was last read and how many busy times it found, for example "Synced 6 min ago, 42 busy times".

Press Sync now when you have just changed the calendar and want to see it on the Space without waiting. Give it a few seconds, then reopen the Space.

If a change still does not show after Sync now, the calendar app has not updated its published link yet. That delay is on the calendar's side, and syncing again will pick the change up once it has.

When a calendar stops syncing

If 1pm cannot read a calendar, the card shows Last sync failed with the reason, and you get a notification on the bell the first time it fails. You are not notified again on every attempt while it stays broken. 1pm keeps trying every 20 minutes, so once the problem is fixed it recovers on its own.

If the calendar closes appointment slots, a failed sync does not reopen them straight away: the busy times from the last successful sync keep closing slots for 48 hours, and the card says so. After 48 hours without a successful sync, the calendar stops closing slots until it syncs again, so a broken link cannot keep clients away from times you are actually free. The busy times still show on the Space either way.

The common reasons, and what to do:

The calendar link returned 404 (or 401, or 403). The link no longer works. This usually means the secret address was reset, or the calendar was unpublished or deleted. Copy the current link from the calendar app, connect it, and remove the old one.
That link didn't return a calendar. The address is a web page, not a calendar feed. A link to view the calendar in a browser will not work. Go back to the calendar's settings and copy the iCal or ICS link specifically.
The calendar is larger than the 5 MB limit. The calendar holds years of history. Most apps let you publish a calendar that covers less, or you can connect a separate calendar that only holds upcoming bookings.
Refusing to connect to a non-public address. The link points at a private network address, such as a server inside your office. 1pm only reads calendars published on the public internet.

Removing a calendar

Press Remove beside the calendar and confirm. Its busy times disappear from the Space immediately. Nothing changes in the calendar itself, and your events and appointments in 1pm are untouched.

To stop 1pm reading a calendar entirely, removing it here is enough. If you also want to be sure nobody else can read it with the old link, reset the secret address in the calendar app.

What a Space is covers everything else on a Space's form.
Preventing a double-booked Space covers the checks that do stop a clash.
Importing bookings from a calendar turns calendar entries into real bookings.
Syncing your calendar sends your 1pm bookings the other way, out to Google, Outlook or Apple Calendar.
Appointments and the booking page covers the slots clients book, and how your availability, bookings and connected calendars decide which ones are open.