calendar-operator

name

calendar-operator

description

This skill should be used when the user asks "what's on my calendar", "am I free Thursday", "add an event", "block time for this", "clean up my test calendar", or "which calendar tool should I use". Covers bounded reads, timezone handling, safe event creation, ID-first updates and deletes, and calendar management with list_calendars, list_events, create_event, delete_events, and manage_calendars. Do NOT use for coordinating meetings with other people or invitation workflows (see meeting-scheduler), and do NOT use for email work (see apple-mail-operator).

Calendar Operator

Operate the Apple Calendar tool surface safely: bounded reads, timezone-correct writes, ID-first mutations, and dry-run-first deletes.

When To Use This Skill

Signal	Skill
Read my schedule, add/edit/delete my own events, calendar cleanup	calendar-operator (this skill)
Find a time with other people, invitations, cross-timezone meetings	meeting-scheduler
Anything email (inbox, drafts, replies)	apple-mail-operator and siblings

Bootstrap

1. Call list_calendars() first. It returns every calendar with calendar_id, writable, is_default, the active engine (applescript or eventkit), and eventkit_available diagnostics.
2. Note the writable calendars. Writes to subscribed or delegated calendars return CALENDAR_READ_ONLY.
3. DEFAULT_CALENDAR (environment variable) sets the create target only; reads always scope explicitly or fan out.

Bounded reads (the core doctrine)

Every event read requires a window and every window is capped. This differs from the mail tools in one important way: with no calendar argument, list_events and check_availability fan out across every calendar (capped at 20 plus a wall-clock budget) instead of erroring like mail's account scoping. Prefer explicit scoping:

• list_events(days_ahead=7) for the upcoming week across calendars.
• list_events(calendar="Work", days_ahead=1, days_back=0) for today on one calendar.
• list_events(start="2026-08-01", end="2026-08-31", query="review") for a bounded search.
• Page with offset when truncated is true; never widen the window instead.

On UNBOUNDED_CALENDAR_SCAN, supply an explicit non-empty window; on CALENDAR_WINDOW_TOO_WIDE, narrow the window; on CALENDAR_WINDOW_TOO_DENSE, narrow further or scope to one calendar. Check calendar_errors and budget_exhausted on every fan-out response; partial results are normal on slow stores.

Recurring coverage (AppleScript engine): list_events and check_availability project recurring occurrences from masters whose start date falls within the last 400 days, so a standing series created earlier can be missing with no per-row error. When the AppleScript recurring pass runs, the response carries recurring_lookback_days and a recurring_coverage_note; if a long-running series looks absent, tell the user it may predate the horizon and that the EventKit fast path expands natively. See references/calendar-safety-limits.md.

Timezones

Pass timezone (IANA, for example America/Chicago) whenever the user's zone matters, and read resolved_timezone back. Events return start/end in the requested zone plus start_utc/end_utc. Naive datetimes are interpreted in the requested zone; offset-aware ISO 8601 strings need no timezone parameter. The event lands on the correct absolute instant regardless of the Mac's own zone.

Creating and editing events

• create_event(title=..., start=..., duration_minutes=60) or an explicit end. All-day: all_day=True (may omit end for one day). Alarms: alarms_minutes_before=[10, 60] (max 5). Recurrence: allowlisted RRULE strings such as FREQ=WEEKLY;BYDAY=MO,WE,FR.
• Conflict detection is on by default (on_conflict="warn" reports conflicts; "block" refuses with EVENT_CONFLICT; "allow" skips).
• Search then mutate by id: update_event and delete_events take exact event_ids from a prior list_events/get_events_by_id call. There are no fuzzy destructive selectors, by design. Pass calendar as a lookup hint to avoid fan-out.
• update_event is PATCH-style: only the fields you pass change. On EVENT_NOT_FOUND, widen lookup_days_back/lookup_days_ahead or pass the right calendar.
• Recurring targets require span='all_occurrences'. update_event applies the change to the whole series; delete_events cannot remove a whole series (Calendar.app scripting deletes only individual occurrences), so it verifies after deleting and returns RECURRING_DELETE_INCOMPLETE with the surviving dates when the series is not fully gone. this_occurrence/future_occurrences return RECURRING_SPAN_UNSUPPORTED.
• batch_create_events creates up to 25 one-off blocking events in one call (no attendees, no recurrence in items); use dry_run=True first for bulk plans.

Destructive red lines

Action	Rule
delete_events	Always run the default dry_run=True preview and show it before dry_run=False; exact ids only; one unresolved id aborts everything
Recurring deletes	Calendar.app scripting cannot remove a whole series; delete_events verifies after running and returns RECURRING_DELETE_INCOMPLETE with surviving dates. For a reliable series delete, direct the user to Calendar.app
manage_calendars(action="delete")	Three steps: dry-run preview with event_count, then confirm_delete_calendar=True, plus force_nonempty=True when events exist; exact name or calendar_id only
Draft-safe mode	Deletes return CALENDAR_DELETE_BLOCKED; never suggest the CALENDAR_ALLOW_DESTRUCTIVE env unlock, that is an operator decision at launch
Bulk anything	Respect TOO_MANY_DELETES / BATCH_TOO_LARGE; split deliberately, never loop to evade caps

Modes: what the flags block here

The mode flags gate calendars harder than mail: --read-only removes every calendar write tool; --draft-safe additionally blocks deletes and attendee sends while still allowing personal create/update/rename (reversible, no third parties). For mail tools the same flags block only the send paths. Read the full matrix in references/calendar-safety-limits.md.

Troubleshooting (TCC and performance)

• First call hangs then times out: a pending Automation consent prompt presents as a silent hang. Have the user open System Settings > Privacy & Security > Automation, enable Calendar under the host app, and retry. CALENDAR_ACCESS_DENIED remediation names the exact pane.
• Slow reads: Calendar.app AppleScript scans cost tracks total store size (community benchmarks: roughly 61 to 112 seconds on modest calendars). The EventKit fast path is roughly 3000x faster and activates automatically when pip install 'mcp-apple-mail[eventkit]' is installed and Calendars full access is already granted; check eventkit_available in list_calendars. A human can grant it once by running apple-mail calendar-grant from Terminal. Never attempt to trigger that consent prompt from a tool call.
• Calendar.app may launch when AppleScript runs; this is normal.
• Call one calendar tool at a time; calls serialize behind the same lock as the mail tools.

Platform gaps (be direct with users)

• Invitations: attendee attachment never guarantees delivery (invitation_delivery: "platform_dependent"); see meeting-scheduler for the reliable .ics drafting path.
• RSVP: respond_to_invitation always returns CALENDAR_RSVP_UNSUPPORTED; point the user to Calendar.app or their mail client.

Additional Resources

• references/calendar-safety-limits.md: bounds, mode matrix, error recovery, platform limitations.