Is there a family calendar app that works with Outlook?

1. Add one event: a copy of the event goes into Outlook. If it changes later, the copy does not.
2. Subscribe to a calendar feed: Outlook shows the other calendar and updates it. Microsoft says subscribed calendars update roughly every 3 hours, and an update can take more than 24 hours.
3. Two-way sync: changes made in either calendar appear in the other.

Microsoft's help page explains the difference between importing a calendar file, which is a one-off snapshot, and subscribing, which keeps updating.

One-click add to Google or Outlook. Two-way sync coming soon. Add any Haevn event to your own Outlook or Google calendar in one click, so a work diary can show the school play. Events in Outlook or Google do not appear in Plan automatically yet.

Keep work and family as two calendars. The family calendar only needs what changes the household's day: the late meeting that means someone else does pick-up, the trip away, the early start. Add that as one plain event, such as "Dad late, Mum doing pick-up", not the meeting itself. In Plan you can create events that only you can edit, which suits personal appointments the household should see but not change.

Haevn runs in the web browser at app.haevn.uk on iPhone, Android, tablets and computers, so a house with mixed phones shares one calendar. You can add it to your home screen so it opens like an app. Native iOS and Android apps are not available yet.