Datum is a minimalistic iOS, watchOS, macOS and visionOS calendar app.

For iOS there are Lockscreen Widgets that show you the current date and there are Lockscreen Widgets that show up to 3 events for today.

The iOS and macOS apps include the following widgets:
- a small widget that shows the current date and at the bottom the events for this day
- a small widget that shows a calendar with up to 3 event marks for each day
- a medium widget that shows the same as the first small widget and on the right side a calendar with up to 3 event marks for each day
- a large widget that shows the same as the medium widget and a list of the upcoming events
- a extra large widget that shows a calendar and a list of the upcoming events (only for iPadOS 15+)

The watchOS app shows a calendar with up to 3 event marks for each day. You can switch to the next/previous month by tapping on the arrows at the bottom of the calendar. You can view all events for each day by tapping on a day. There are also complications for all watchfaces included that show you the current date.