Everything else

Start from what you are seeing rather than from what you think is broken. Each page below names the symptom, explains why it happens, and says what to do about it.

Several of these are the product working as designed, which is worth knowing before anybody raises a ticket.

#At a glance

Symptom	Usually because
Switched all the event types off, but the calendar still shows everything	With no event types selected, the filter is not applied at all, so every source is shown.
Turned off "Confluence Date macros", but dates inside action items still appear	That switch does not cover dates inside action items. It only applies to dates in paragraphs, table rows and standalone date chips.
Several dates in one paragraph (or one table row) turned into a single event instead of several	By design, a paragraph or a table row makes one event running from the earliest to the latest date in it.
Date chip on a line by itself never appears on any calendar	A date with no surrounding text is named "Unknown", and events named "Unknown" are filtered out everywhere.
Colleague in another country sees the event at a different time or on a different day	The calendar always shows events in the viewer's own timezone. A calendar's "Base Timezone" only pre-fills the timezone when you create or edit an event; it does not change what the calendar shows.
Event macro pill shows a time that looks shifted by the timezone offset (for example 14:00 showing as 09:00)	A known bug: when the macro has a timezone set, the time is converted twice. The date is still right.
Set a Base Timezone on a calendar and nothing changed	Either it is doing its job, which is only to pre-fill the event editor, or the saved zone is not one the app recognises. In that case it quietly falls back to the viewer's own zone without showing an error.
Repeating meeting in my subscribed calendar app only appears once	The feed sends each event once and does not include its repeats. Recurring events imported from an .ics file also keep only their first occurrence.
Edited an event but my phone's calendar has not updated	A short delay is normal. Changes usually reach your subscribed calendar app within 5 to 15 minutes of your edit. If it has been more than 15 minutes, refresh the calendar in your app.
Subscribed calendar has not changed for days even though the calendar is active	If no calendar app has checked a feed for 3 days, it is rebuilt from scratch the next time one does. And if Confluence cannot be reached, the feed can keep serving a copy up to 24 hours old.
Person removed from the space could still see the calendar feed for a while	Access to a feed is re-checked at most once an hour, so a removed person can keep reading it until the next check.
Someone who should not have it has my feed URL	A feed URL works like a password. Anyone holding the link can read that calendar's events without signing in.
Turned off the "Calendar subscriptions" feature but existing links still work	The toggle only blocks creating new links; it does not revoke ones already handed out.
"Dates" column and the Calendar panel badge in Capable Search show fewer dates than the page has	Those two cannot recognise Capable Event macros, so they count only Confluence's own dates. The page byline counts both.

The first two symptoms both come down to the Event types setting in the Calendar macro. Here is where it lives.

Calendar macro Events section showing the three event types and the Hidden on page events picker — The Event types in the Calendar macro. With none selected, every source is shown. Use Hidden on-page events to leave out a single date.

#In this section

Switched all the event types off, but the calendar still shows everythingI switched all the event types off, but the calendar still shows everything.Turned off "Confluence Date macros", but dates inside action items still appearI turned off "Confluence Date macros", but dates inside action items still appear.Several dates in one paragraph (or one table row) turned into a single event instead of severalSeveral dates in one paragraph (or one table row) turned into a single event instead of several.Date chip on a line by itself never appears on any calendarA date chip on a line by itself never appears on any calendar.Colleague in another country sees the event at a different time or on a different dayMy colleague in another country sees the event at a different time or on a different day.Event macro pill shows a time that looks shifted by the timezone offset (for example 14:00 renderingAn Event macro pill shows a time that looks shifted by the timezone offset (for example 14:00 rendering as 09:00), while the date is right.Set a Base Timezone on a calendar and nothing changedI set a Base Timezone on a calendar and nothing changed.Repeating meeting in my subscribed calendar app only appears onceA repeating meeting in my subscribed calendar app only appears once.Edited an event but my phone's calendar has not updatedI edited an event but my phone's calendar has not updated.Subscribed calendar has not changed for days even though the calendar is activeA subscribed calendar has not changed for days even though the calendar is active.Person removed from the space could still see the calendar feed for a whileA person removed from the space could still see the calendar feed for a while.Someone who should not have it has my feed URLSomeone who should not have it has my feed URL.Turned off the "Calendar subscriptions" feature but existing links still workI turned off the "Calendar subscriptions" feature but existing links still work."Dates" column and the Calendar panel badge in Capable Search show fewer dates than the page hasThe "Dates" column and the Calendar panel badge in Capable Search show fewer dates than the page has.

Troubleshooting

Every symptom.

Reference

Limits and gaps.

How it works

The behaviour.

Most of these are expected behaviour.