Export a calendar as a portable ICS tree.

Each event lands as <calendar>/<date>_<subject>_<id>.ics plus a JSON sidecar carrying what iCalendar cannot (Graph ids, the recurrence object, the online-meeting provider, sensitivity/importance), and the run ends with a manifest.jsonl index. .ics opens in Outlook, Google Calendar and Thunderbird, so the export is both an archive and the input for an import.

The job is the same MigrationJob the SharePoint and mail adapters use, so it plans, resumes and verifies: a re-run skips what is already on disk, and verify() compares each .ics checksum against the document rendered from the source event.

Permissions

Requires delegated permission Calendars.Read.

Reference

• https://learn.microsoft.com/en-us/graph/api/user-list-events

View source

import argparse
import tempfile
from pathlib import Path

from office365.graph_client import GraphClient
from office365.migration import MigrationJob, MigrationOptions
from office365.migration.outlook import CalendarExportOptions, CalendarSource, IcsExportTarget
from tests.settings import client_id, password, tenant, username


def main():
    parser = argparse.ArgumentParser(description="Export a calendar to an ICS tree")
    parser.add_argument("--calendar", default=None, help="calendar id (default: the user's default calendar)")
    parser.add_argument("--output", default=None, help="output directory (default: temp dir)")
    parser.add_argument("--root-name", default=None, help="top folder name (default: the calendar's display name)")
    parser.add_argument("--instances", action="store_true", help="also export recurring occurrences/exceptions")
    parser.add_argument("--cancelled", action="store_true", help="also export cancelled events")
    parser.add_argument("--preserve-timestamps", action="store_true", help="stamp each .ics with its modified time")
    args = parser.parse_args()

    client = GraphClient(tenant=tenant).with_username_and_password(client_id, username, password)
    calendar = (
        client.me.calendars[args.calendar].get().execute_query()
        if args.calendar
        else client.me.calendar.get().execute_query()
    )
    output = Path(args.output or tempfile.mkdtemp(prefix="calendar-export-"))

    options = CalendarExportOptions(
        root_name=args.root_name,
        include_recurring_instances=args.instances,
        include_cancelled=args.cancelled,
    )
    job = MigrationJob(
        CalendarSource(calendar, options),
        IcsExportTarget(output),
        options=MigrationOptions(preserve_timestamps=args.preserve_timestamps),
    )

    job.plan()
    print(f"Planned {len(job.manifest)} events from {calendar.name}")
    stats = job.run()
    print(stats.summary())
    print(job.verify().summary())
    print(f"Export written to {output}")


if __name__ == "__main__":
    main()

---

← Back to Export a mailbox, a calendar or contacts