Connecting an outside calendar to a Space — Help

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. 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.
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 does not block anything. A busy time from an outside calendar never stops you saving an event, never raises a double-booking warning, and never removes a slot from your appointment booking page. 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:// or webcal://. Both work, and 1pm reads a webcal:// link over a secure connection.

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.

Times are shown as the calendar holds them, in the calendar's own time zone. Most calendars publish their home time zone, and 1pm uses it to show a 5pm booking as 5pm. If your calendar is set to a different time zone from the Space, the busy times will read in the calendar's zone, so check the calendar's own time zone setting if they look a few hours out.

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.

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, which are worked out from your availability and never from connected calendars.