Microsoft 365 Calendar

CLI tool for Microsoft 365 Calendar via Microsoft Graph API.

Setup

Uses the same client/tenant from m365mail. Just authenticate with calendar scope:

# Authenticate (device code flow)
m365cal auth

If you haven't set up m365mail yet, do that first — the calendar tool shares its config.

Required Permissions

In your Entra ID app, add these Graph permissions:

Calendars.ReadWrite (delegated)

Commands

View Events

m365cal today                     # Today's events
m365cal tomorrow                  # Tomorrow's events
m365cal week                      # Next 7 days
m365cal range 2024-01-15          # Specific date
m365cal range 2024-01-15 2024-01-20  # Date range
m365cal show <event_id>           # Event details

Create Events

# Simple event
m365cal create -s "Team standup" --start "2024-01-15 09:00" -d 30

# With location
m365cal create -s "Lunch" --start "2024-01-15 12:00" -d 60 -l "Cafe"

# With attendees (sends invitations automatically)
m365cal create -s "Project review" --start "2024-01-15 14:00" -d 60 \
  -a alice@company.com bob@company.com \
  -o carol@company.com

# Teams meeting with attendees
m365cal create -s "Sprint planning" --start "2024-01-15 10:00" -d 90 \
  -a team@company.com --teams

# All-day event
m365cal create -s "Conference" --start "2024-01-20" --all-day

Update Events

m365cal update <event_id> --subject "New title"
m365cal update <event_id> --start "2024-01-15 15:00"
m365cal update <event_id> -l "Room 201"

Updates with attendees automatically send update notifications.

Delete/Cancel Events

m365cal delete <event_id>                    # Silent delete
m365cal delete <event_id> -m "Rescheduling"  # Cancel with message to attendees

Respond to Invitations

m365cal respond <event_id> accept
m365cal respond <event_id> tentative -m "Might be late"
m365cal respond <event_id> decline --silent  # Don't notify organizer

List Calendars

m365cal calendars
m365cal calendars --json

Options

-v, --verbose: Show more details
--json: Output as JSON (for scripting)
-d, --duration: Duration in minutes (default: 60)
-a, --attendees: Required attendees (emails)
-o, --optional: Optional attendees
-t, --teams: Create Teams meeting
-l, --location: Location
-b, --body: Description/notes

Meeting Invitations

When you create or update an event with attendees, Microsoft Graph automatically:

Sends meeting invitations via email
Adds the event to attendees' calendars (pending acceptance)
Sends update/cancellation notices when changed

No need to use m365mail separately — invitations are built into the calendar API.

Event IDs

Events are identified by long IDs. Commands accept:

Full ID
ID prefix (first 8+ chars usually unique)

Token Storage

Config (shared): ~/.m365mail/config.json
Calendar tokens: ~/.m365calendar/token_cache.json

Troubleshooting

"No cached token": Run m365cal auth

"Run m365mail setup first": Calendar shares credentials with mail. Set up mail first.

Permission denied: Ensure Calendars.ReadWrite permission is granted in Entra ID.

m365-calendar