Showing one client only the part of your calendar that concerns them

You have one calendar, because one calendar is how a life works. But the person asking for your availability only has business with a tenth of it — and you would rather not hand over the other nine.

A referee wants an assignor to see which Saturdays are open for matches, not the christening. A contractor wants one client to see the days booked for their project, not the other clients’ names. A tutor, a photographer, a locum, a translator: same shape every time. Some slice of your week is theirs, and the rest is emphatically not.

Tag what is theirs, mirror only that

Put a tag in the notes of the events that concern them, and give the mirror a rule that copies only tagged events. Everything else in your calendar stays where it is. The destination is a calendar you share with that one person, and it fills up with exactly the blocks they are entitled to see.

The setup

  1. Pick a tag. A hash and a word: #ref, #acme, #clinic. Type it into the notes of each event that belongs to that relationship — not the title.
  2. Make a calendar, share it with that person, and pair your main calendar to it.
  3. Give the pair a selective-copy rule: include, tag #acme. Only events carrying that tag are copied. No rule at all copies everything, which is not what you want here.
  4. Choose the projection. Busy only if they just need to know the day is taken; Copy details if the title is the point.

Tags are matched case-insensitively and as whole words, so #ref and #ref-cup are two different tags — which is how you run several of these side by side. One event can carry several tags, and a second mirror with its own rule picks up its own subset. The tags themselves are stripped from the copies unless you ask to keep them.

The other direction: everything except

Sometimes the sensible rule is the inverse. A reject rule copies everything except the events you tagged — useful when the shared calendar is mostly complete and a handful of things must never appear. And #nomirror in an event’s notes keeps a single event out of every mirror at once, including removing a copy it already made.

The gotcha everyone hits once. The Copy details preset does not copy notes — so if you also want the tag itself to arrive at the destination, choose Full copy, or the custom setting that sends tags only. That last one puts just the tags in the copy’s notes and leaves your actual prose behind, which is usually what you meant.

What this doesn’t fix

Tags live in the notes of events you can edit, so they only work on your own calendars — a subscribed feed can’t be tagged, and for those you select on the event’s own properties instead: all-day, declined, free, duration, a word in the title, or a time-of-day window. And tagging is a habit: an event you forget to tag doesn’t cross over. For most people that is the right failure — silence rather than a leak — but it is worth knowing which way it fails.

Get Calendar Mirror — $2.99 What it does

One purchase covers iPhone, iPad and Mac. No accounts, no ads, nothing collected. macOS 14 or iOS 17 and up. The Mac version is also free to build from source.

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