mcp-calendar

mcp-calendar

Your calendar app can show you next Tuesday. It cannot tell you where your week actually went, which two things yousaid yes to at the same time, or how many billable hours last month's meetings were worth. This server reads the.ics file your calendar already exports and answers those questions: events in any window with recurring seriesexpanded properly, merged busy blocks and the real free gaps inside your working hours, every double booking acrosswork and personal calendars at once, a clean .ics of just the events you picked, and the exact time entry for ameeting you should have billed. No account is connected, nothing is synced, and the calendar file stays on yourmachine as plain text.

Built by theluckystrike.

Import the .ics your calendar exports, then ask what is on, when you are free, and what clashes -- zero setup, all local.

60-second install

npm publish for @theluckystrike/mcp-calendar is pending. Until then, the .mcpb one-click bundle or a clone+buildis the working path -- both are verified below.

One-click (.mcpb): download calendar.mcpb from the latest release and double-click it in Claude Desktop:https://github.com/theluckystrike/mcp-servers/releases/latest

Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "calendar": {
      "command": "npx",
      "args": ["-y", "@theluckystrike/mcp-calendar"]
    }
  }
}

Claude Code:

claude mcp add calendar -- npx -y @theluckystrike/mcp-calendar

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "calendar": {
      "command": "npx",
      "args": ["-y", "@theluckystrike/mcp-calendar"]
    }
  }
}

The npx form above starts working the moment the package is published. Until then, use the .mcpb bundle above,or build from source with exactly these four commands:

git clone https://github.com/theluckystrike/mcp-servers.git && cd mcp-servers
npm install
npm run build -w packages/mcp-license -w servers/timezone -w servers/calendar

Then point your client's command at node with one arg: the absolute path to servers/calendar/dist/index.js.

To run in Pro mode set MCP_LICENSE_KEY in the same config block, or call license_activate once with your key.

Getting the .ics out of your calendar

Then: ics_import {path: "~/Downloads/[email protected]", name: "work"}

Tools

Resource calendar://today gives today's schedule in one read. Prompt plan_my_day walks the whole loop: what is on,what clashes, where the free stretches are, and which finished meetings to bill.

What the parser handles

Written against real exports, not just the spec: line folding (CRLF, bare LF and bare CR, and folds that Exchangeplaces inside a multi-byte character, which are rejoined on the bytes before decoding), \n \, \; \\ escaping,whole-day events with an exclusive DTEND, DURATION instead of DTEND, TZID and UTC times, floating times,RRULE for HOURLY, DAILY, WEEKLY, MONTHLY and YEARLY with COUNT, UNTIL (inclusive), INTERVAL,BYDAY including ordinals (2MO, -1FR), BYMONTHDAY, BYMONTH and BYSETPOS, EXDATE, RDATE,RECURRENCE-ID overrides (the moved instance replaces the original instead of appearing twice),STATUS:CANCELLED, TRANSP:TRANSPARENT, and VALARM blocks inside an event. An event it cannot read is skippedand counted rather than costing you the rest of the file.

FREQ=MINUTELY and FREQ=SECONDLY are deliberately not expanded: one such rule fills any window with thousands ofoccurrences and buries the rest of the week. Those events are listed at their first occurrence and the reason issaid out loud. A rule with no COUNT and no UNTIL is expanded only as far as the window you asked for.

Exports written by this server keep whole-day events as DATE values, so a holiday leaves as the same day itarrived rather than a timed block on the day before in your machine's zone.

VTIMEZONE is deliberately ignored. A file's inline DST rules are only as fresh as the app that wrote it; the TZIDis kept and every offset is computed from the ICU data inside your Node build instead, which is what keeps a weeklyWarsaw 10:00 meeting at 10:00 local across the March clock change.

Free vs Pro

Get Pro -- or $39 for every server in the suite, lifetime.

Privacy

Everything is local. The calendar file you import is copied to${XDG_DATA_HOME:-~/.local/share}/mcp-servers/calendar/ and read from there; deleting that directory resets theserver. There is exactly one network call in the whole server, and only when you pass a url yourself: it fetchesthat address once, with a 12-second timeout, a 5 MB cap, and a refusal on loopback, private and cloud-metadataaddresses. Nothing is uploaded, no account is linked, and licence keys verify offline.

Pairs with

• mcp-timezone -- this server reads its time zone and .ics engine from it: convert a meeting time, find slots across countries, write an invite.
• mcp-time-tracker -- event_to_time_entry hands it a finished meeting; it tracks and reports the hours.
• mcp-invoice -- turn those tracked hours into a numbered invoice.
• office-suite -- several servers behind one install, one config entry.

FAQ

Does it connect to my Google or Outlook account?No. There is no OAuth, no token and no sync. You export a file (or paste a public feed URL on Pro) and it is readlocally. That also means an import is a snapshot: re-import when the calendar has moved on.

Do recurring events work properly?Yes, and that is most of the code. A weekly series is expanded on the wall clock, so a Warsaw 10:00 meeting stays10:00 through the DST change rather than drifting to 11:00. Monthly on the 31st skips February instead of rolling intoMarch, UNTIL includes the occurrence that falls exactly on it, and a single moved instance replaces the original.

Why is my whole-day event one day shorter than I expected?It is not: RFC 5545 makes DTEND exclusive for a whole-day event, so 1--3 June means the 1st and the 2nd. Thisserver follows the spec, which is what your calendar app does too.

Can it write to my calendar?It writes .ics files with event_export, which you can import anywhere. It never modifies the calendar it read.

How big a file can it read?5 MB, which is a few thousand events. Export a narrower date range if a full history is bigger than that.