Feeds that run on their own — a calendar you bring into Longtime, which proposes connections and occasions for your review, and feeds of your birthdays or connections that you publish to the calendar you already use.

Constant Bridges are calendar feeds that keep running once you set them up. A feed is a web address for a calendar. Paste a calendar's address into Longtime, and Longtime reads it; paste Longtime's address into your calendar app, and your calendar shows the birthdays of the people in your Space, or your connections with them, kept up to date. Open them from the Bridges hub.

The rule: what arrives becomes suggestions. Nothing changes without you.

Bring a calendar into Longtime

Give Longtime a calendar's address, and the events in it that you shared with other people are proposed as connections for you to review.

In your calendar app, find the calendar's iCal address — it ends in .ics. Google Calendar calls it the "Secret address in iCal format"; in Apple Calendar, share the calendar as a public calendar and copy its link (one that starts with webcal:// works as it is).
In the section for bringing data in, add one, paste the calendar's address, and give it a name if you like.
Create it.

Longtime reads the calendar about once a day, overnight, and when you first add it; you can sync it yourself whenever you want it sooner. A sync you start yourself counts as that day's read, so the next automatic one may come a night later. What it finds lands in your Suggestions inbox, marked "From a calendar feed". Only events that look like time with another person are proposed — a focus block or a reminder you set yourself is left out — and people it does not recognize are suggested as new people.

An all-day event, or a timed one that lasts a day or more, with someone else on it — a weekend away, a wedding — is proposed as an occasion rather than a connection, with the invitees as the people on it. If Longtime reads one the wrong way, switch it to an occasion or a connection from its card, and the switch sticks on later syncs.

If an event you already accepted is canceled in the calendar, Longtime asks whether to remove the connection or occasion, and keeps it unless you say so.

Removing the feed stops Longtime reading that calendar. Connections you already accepted from it stay, and suggestions it already made stay in your inbox for you to decide on.

Nothing goes back to the calendar

Bringing a calendar in only reads it. Longtime never writes to that calendar, and nothing about your Space is sent there.

Show Longtime on your calendar

Your Space can go the other way too, as a feed your calendar app subscribes to — so what is in Longtime appears on the calendar you already look at. There are two to choose from:

Birthdays — everyone's birthdays, every year.
Connections — your connections at their times, with occasions as all-day events across their days.

In the section for sending data out, add one, pick birthdays or connections, and name it if you like.
Create it. The feed starts publishing.
Copy the feed's URL, and add it to your calendar app as a subscribed calendar (in most apps: "Add calendar → From URL").

The URL is the key

Anyone who has a feed's URL can read it, so treat it the way you would any other secret link. To shut it off, remove the feed — the URL stops working — and add a new feed if you still want one.

Removing a feed stops new updates, but it cannot reach into your calendar app. Events your calendar has already copied from the feed can stay there until you remove the subscribed calendar in that app yourself.

Details

A calendar holds much more than the times you saw people, and every entry that is not one would cost you a card to dismiss. So the rules for what becomes a suggestion are strict, and each is about the same question — was this time with a person?

Someone besides you has to be on it. A focus block or a reminder you set yourself is left out.
A person, not a room. Meeting rooms, equipment and mailing lists on an invite do not count as people.
Not declined, not tentative. Guests who declined are not counted, and an event marked tentative waits until it is confirmed.
Not too long ago. Longtime looks back about three months; older events are left alone. Upcoming one-off events are proposed as planned connections; a repeating meeting comes in occurrence by occurrence, as each one happens.

Guests are matched to your people by email address, whatever its capitals — or, for a calendar exported from Longtime, by Longtime's own ID. Someone whose email you have not saved in Longtime is suggested as a new person.

Each occurrence of a repeating meeting is suggested on its own, once it has happened. If you do not want a series at all, choose to dismiss the whole series on its suggestion card; that stops it from every calendar in your Space.

When the calendar changes:

Moved or retitled — a suggestion still waiting is updated in place.
Canceled before you accepted it — the suggestion is withdrawn.
Canceled, or marked tentative, after you accepted it — Longtime asks whether to remove the connection or occasion, and keeps it unless you say so.
Un-canceled — the question is withdrawn.

If Longtime cannot read a feed, the feed's row says so, and the Bridges hub lists it under Needs you. It keeps trying about once a day. If the calendar's address has changed, remove the feed and add the new one.

Longtime rebuilds each published feed about once a day, overnight, and refreshing it rebuilds it straight away — a refresh counts as that day's rebuild, so the next automatic one may come a night later. Your calendar app checks for changes on its own schedule.