Using Hotmail, Outlook.com, Office 365, Microsoft 365 or a corporate Exchange account? Here is how to get your calendar into aCalendar.

1

How it works

aCalendar does not connect to Microsoft directly. The sync between your Microsoft account and Android is handled by Android itself – aCalendar just displays the result. You set up your account in Android’s settings, not inside aCalendar.

Android has built-in support for Microsoft Exchange. On many phones you can choose between Google’s Exchange implementation (provided via the Gmail app) and one from the phone manufacturer (often called ActiveSync or Enterprise Sync).

2

Recommended setup

Use Android’s built-in Exchange sync for the most reliable connection. Follow these steps:

1

Open Android account settings

Go to Settings → Accounts on your Android phone.

2

Add a new account

Tap Add account and select Exchange as the account type.

3

Choose manual configuration

Select manual configuration when prompted. You can ignore any warning suggesting you go back and select “Outlook, Hotmail and Live”.

4

Enter the server address

Use m.outlook.com as the server address for all Microsoft cloud services (Hotmail, Outlook.com, Office 365, Microsoft 365).

3

Using the Outlook app

The Microsoft Outlook app for Android can sync your calendar to aCalendar. To enable this, open the Outlook app and make sure Sync Calendars is turned on in the settings.

Note: Outlook’s sync has several known limitations (see section 4 below). If you run into problems, the built-in Android Exchange sync (section 2) is usually more reliable.

More info: How do I sync my Outlook Calendar to the default calendar app?

4

Known issues

These are known limitations that are caused by the respective sync implementation – not by aCalendar.

Android Exchange sync: Limited sync of past events Android / Manufacturer

Some manufacturers limit how far back past events are synced. This is sometimes configurable in the account settings or Gmail app settings – often linked to how far back emails are synced.

Android Exchange sync: No attachment support Android

Android does not support syncing file attachments for Exchange calendar events.

Android Exchange sync: No “Out of Office” availability Android

Android does not natively support the out-of-office availability field. We are working on support for proprietary solutions where this is implemented by the phone manufacturer.

Samsung ActiveSync: Sync to Outlook not working Samsung

Samsung’s ActiveSync fails to sync new or modified events that have an Outlook category assigned. The last Samsung email app version known to work correctly is 6.1.11.6 (available on APK Mirror).

Samsung ActiveSync: Exchange calendar disappears after restart Samsung

In Ultra Power Saving Mode, Samsung devices may lose the Exchange calendar after a restart. To fix this, open the Samsung Email app to re-grant Exchange admin permissions and re-enable calendar sync. This is a known Samsung firmware bug.

Google Exchange sync: Duplicate calendar entries Google

Some users see double or triple entries in their Exchange calendar. Fix: remove the account in Android account settings and add it again.

Google Exchange sync: Calendars appear twice or deleted calendars still show Google

Google’s Exchange sync sometimes shows deleted calendars without marking them as deleted. Go to the Calendar List and deactivate the duplicates.

Google Exchange sync: Shared / sub-calendars missing Google

Google’s Exchange sync only synchronizes the main calendar for some account and server types. Shared or sub-calendars may not appear.

Outlook app sync: Several limitations Outlook app

The Outlook app sync has a number of known limitations:

  • Only syncs the values free, busy and tentative – not away/elsewhere
  • Does not sync Outlook categories
  • Does not sync the private status of events
  • All-day events are synced one day too long
  • Outlook modifies the description field in a way that breaks aCalendar’s event colors and contact linking