Summary

Connect Microsoft Outlook Calendar to Alta Flows to create, list, and delete calendar events directly from your workflows — useful for booking holds after a meeting is set, surfacing upcoming events in another tool, or cleaning up canceled bookings without leaving Alta.

Who this is for: Anyone building or editing an Alta Flow who wants Outlook Calendar steps. You need a Microsoft 365 account whose calendar you want Alta to read or write to.

Before you start

You'll need a Microsoft 365 sign-in (work or school account) with access to the Outlook calendars you want to manage.
You'll need permission to create Flows in your Alta workspace.
Microsoft Outlook Calendar in Alta is a Flows integration — it's not part of Alta's native CRM sync layer, and it doesn't replace the Gmail / Outlook mailbox connection you set up under Settings → Katie's Reps for sending campaign email.

Step 1 — Connect Microsoft Outlook Calendar

Open Flows in Alta and start a new flow (or edit an existing one).
Add a step and pick Microsoft Outlook Calendar from the integration list.
When prompted, click Connect. A Microsoft sign-in window opens.
Sign in with the Microsoft 365 account whose calendar Alta should access, then click Accept to grant the requested permissions.
You're returned to Alta with the connection saved. You can reuse this connection across as many flow steps as you need.

Step 2 — Pick an action

The Microsoft Outlook Calendar integration ships with three actions. All three require you to first pick a Calendar from a dropdown — Alta pulls the live list of calendars from your Microsoft account, so the calendar you choose must be one you can already see in Outlook.

Action: Create a new event in a calendar

Use this when you want a flow to book a calendar entry — for example, blocking out time after a meeting is confirmed in another tool.

Calendar (required) — pick the destination calendar.
Title of the event (required) — the event subject as it will appear in Outlook.
Start date time of the event (required) — when the event starts.
End date time of the event (optional) — when it ends. By default it'll be 30 min post start time if you leave this blank.
Timezone (required) — pick from the dropdown. Alta loads the list of timezones supported by your Outlook account, so the value must match one Outlook recognizes.
Location (optional) — free-text location or meeting link.

Action: List events in a calendar

Use this when you want a flow to read what's already on the calendar — for example, to surface today's meetings in a Slack digest.

Calendar (required) — pick the calendar to read from.
Filter (optional) — narrow the results using Microsoft Graph's $filter syntax. Example: start/dateTime ge '2026-05-20T00:00:00' to only return events starting on or after that date. Full filter reference: Microsoft Graph filter query parameter.

Action: Delete an event in a calendar

Use this to remove an event programmatically — for example, when a meeting is canceled in your CRM and you want the Outlook hold cleared automatically.

Calendar (required) — pick the calendar containing the event.
Event ID (required) — the unique Microsoft Graph event ID. The easiest way to get this is to map it in from a previous List events in a calendar step.

Tips and common pitfalls

Pick a real timezone from the dropdown. Alta pulls the list directly from your Outlook account (supportedTimeZones), so values like Pacific Standard Time or UTC will appear in the dropdown — don't type free text.
If your end time looks wrong, check whether you set one. Leaving End date time of the event blank produces a 30-minute event starting at your Start date time. To make a longer event, set both fields.
To delete an event you need its Event ID, not its title. Chain a List events step first, filter to the event you want, and feed the resulting id into Delete event.
Calendar dropdown is empty? The connection isn't authenticated yet — disconnect and reconnect the Microsoft account, or confirm the account you signed in with actually has calendars in Outlook.
This integration uses Microsoft Graph. If a step fails, the error message Alta surfaces will come from Graph. Most failures map to either an expired token (reconnect) or invalid filter syntax (see the linked Graph filter docs).
One connection is enough. The same Microsoft Outlook Calendar connection works for Create, List, and Delete steps across any number of flows.