Most calendar confusion comes from two things being called the same word: the event in your calendar and the copy of it in everybody else's. Knowing which one you are editing explains nearly every surprise.
An event is the entry in one calendar; an invitation is a request to put a copy of it in somebody else's. Editing your own copy of an invitation changes nothing for anyone else, which is why a private note on a shared meeting stays private.
An .ics file is a calendar entry in the iCalendar format, the standard every calendar application can read. Attaching one to an email is the most reliable way to send an event to somebody whose calendar system you do not know.
CalDAV is the protocol calendar applications use to sync events with a server, so a change on a phone appears on a laptop. It is what makes a calendar shared between devices rather than stored on one.
RSVP is the attendee's answer — yes, no or maybe — sent back to the organiser. A 'maybe' is genuinely useful information and worth sending rather than leaving blank, because an unanswered invitation is indistinguishable from an unread one.
Only the organiser, in most systems. Attendees changing their own copy creates a local-only edit that quietly diverges from everyone else's, which is why times sometimes disagree between two people looking at 'the same' meeting.
The organiser is notified and the event is usually removed or greyed out in your calendar. Declining is also how availability stays accurate: a meeting you are not attending should not be blocking your time.
A tentative event is one you might attend, shown differently and usually treated as free time by scheduling tools. It is the honest answer when you have not decided, and better than accepting and not turning up.
Busy and free are the availability flags other people can see without seeing your details. Marking a personal appointment as busy tells colleagues not to book you without telling them why.
An all-day event covers a whole calendar date rather than a span of hours, and has no time zone. That is why an all-day event stays on the same date when you travel, while a timed event moves.
Usually because it was created as a timed event spanning midnight, or because it was created in a different zone. All-day events should carry a date only; adding times reintroduces the zone problem they exist to avoid.
An overlay shows several calendars together in one view, each in its own colour — work, personal, a partner's. It is how you see conflicts between parts of life that are stored separately.
Keep them separate but visible together. Merging them loses the ability to share one without the other; hiding one means booking over the dentist.
Subscribing adds a read-only calendar that updates itself — a team's holidays, a sports fixture list, public holidays for a country. You cannot edit a subscribed calendar, which is usually the point.
It is what other people see about a new event unless you say otherwise: typically the full details inside a team, and busy-or-free outside it. Getting this setting right once prevents a lot of individual decisions later.
Because the calendar's sharing level grants full details rather than free-busy. Sharing levels are per calendar, so the fix is to move private events to a calendar shared at a lower level rather than to edit each one.
A room resource is a calendar for a place rather than a person, which can be invited like an attendee and accepts or declines based on whether it is free. It is how double-booked rooms are avoided.
The organiser owns the event and can change it; attendees receive it and answer. Transferring an organiser role is awkward in most systems, so it is worth creating recurring meetings from an account that will outlast one person's role.
A delegate is someone allowed to manage your calendar on your behalf — accepting invitations, creating events, sometimes replying as you. It is the formal version of 'ask my assistant', and it is auditable.
The usual causes are the organiser cancelling it, a declined invitation being removed automatically, or a sync conflict resolving in favour of another device. A calendar with a change history makes the difference visible.
It fixes the event to a real moment rather than to a clock reading, so it stays correct when you travel or when the clocks change. Without one, 9am means 9am wherever the device happens to be.
They should, if the viewers are in different zones — that is correct behaviour. They should not if the viewers are in the same zone, which usually means one copy was edited locally.
A feed URL publishes a calendar as a file other applications can subscribe to. Treat it as a secret: anyone with the link can read the calendar, and it usually cannot be revoked per person.
Indefinitely, in most systems, though some only sync a rolling window to devices. The past is worth keeping: it is the only honest record of where time actually went.
A reminder is attached to the event and follows it everywhere; a notification is the delivery of that reminder on one device. Changing when you are reminded affects all devices; muting one device does not change the event.
A link to them should. Putting notes in the description means they are only findable by someone who remembers when the meeting was, which is the hardest thing to remember about it.
A buffer is deliberately protected time on either side of a meeting, for travel, notes or breathing. Booked as a real event it works; left as an intention it gets filled.
Because meetings are booked and work is not. Work that is not on the calendar is invisible to everyone scheduling against it, including you.
Calendar bankruptcy is clearing every recurring meeting and re-adding only those someone asks for. It is drastic and occasionally the only way to find out which of them were still needed.
As many as there are audiences for them — typically work, personal, and one shared with a household. Adding a calendar per project usually creates more colours than insight.
A calendar holds commitments at a time; a list holds intentions without one. Work moves from one to the other when you decide when it will happen, and a task that never makes that move never happens.
Yes — multiply the attendees' hourly cost by the duration. A weekly hour with eight people is over 400 person-hours a year, which is the figure that ends most recurring meetings.
Colour shows the shape of a week at a glance — how much is meetings, how much is focused work, how much is personal. It is worth using for kinds of time rather than for projects, because the kinds are what you want to rebalance.
Daykite is a calendar that holds meetings, routines, tasks and goals together, with an assistant that shows you every change before it makes it. Free for one person.