RESOURCES: ONLINE BOOKING

External calendars: connect your diary via ICS

4appointments connects to other calendars only through ICS links, an open format that Google Calendar, Outlook and Apple can generate and read. Changes made in the external calendar do not change the bookings. This page explains what the connection actually does.

What is possible and what is not

There are three things: importing busy times from an external calendar, importing a one-off ICS file as confirmed bookings, and exporting each provider’s diary. There is no sync with Google Calendar or Outlook, and no connection by signing in with an account. “External calendar” is simply the name the panel gives to a connection through an ICS link. If you edit or delete an event in the external calendar, the bookings in 4appointments are not changed. Anyone who uses Google Calendar or Outlook therefore keeps personal commitments in that app and uses 4appointments for the booking diary.

  • Importing busy times from another calendar through an https ICS link
  • Importing a one-off ICS file as confirmed bookings
  • Exporting each provider’s diary as an ICS link
  • No sync with Google Calendar or Outlook, and no sign-in with an account

Importing busy times and ICS files

In the “External calendar” section, a team member can subscribe to the calendar they already use, and its events then block those times in availability, so nobody books over them. Each member can subscribe to up to 3 calendars. Only busy events block a slot; events marked as free are ignored. The calendar is read again roughly every 15 minutes, so updates are not instant. A one-off ICS file can also be imported as confirmed bookings, but only events starting within the next 60 days are brought in, the file cannot exceed 2 MB, and past or overlapping events are ignored. The event title becomes the client name, and no email addresses or phone numbers are imported. Because the import is one-off, later changes in the old calendar do not come across, so check the result before you give up the old diary.

Taking the bookings onto your phone

Each provider has their own ICS link for export. Subscribe to it from your phone’s calendar and the bookings appear alongside your personal commitments. How often the calendar refreshes is decided by your calendar app, not by 4appointments. Each team member’s own link shows only their bookings, and the link also lets you check the diary on a computer without opening the panel.

  • Subscribe to the provider’s export link from any calendar app that accepts ICS
  • How often the phone calendar refreshes depends on your calendar app
  • The free note the client wrote when booking may appear in the event description
  • Anyone with the address can subscribe to it, so treat the link as confidential

Common questions

Does 4appointments sync with Google Calendar?

No. What exists is subscribing to an ICS link, which imports busy times, and the ICS export of each provider’s diary. A change in Google does not change the bookings.

Does it work with Outlook or Microsoft 365?

Only through an ICS link, like any other calendar. There is no native connection and no sign-in with a Microsoft account.

How long does a change take to show up?

External calendars are read again roughly every 15 minutes. For the phone export, the interval depends on the calendar app you use.

Can my clients see my personal calendar?

No. Imported events only block times in availability; clients see only the free slots.

Want to avoid bookings on top of your own commitments?

Try 4appointments and connect your calendar via ICS. The first 12 months are free, no card needed (see the pricing page).

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