A simple calendar with optional CalDAV synchronization. You can easily create recurring events and setup reminders, it can also display week numbers.

Contains a monthly view and an event list widget where you can customize the color of the text, as well as the alpha and the color of the background.

Contains no ads or unnecessary permissions. It is fully opensource, provides customizable colors.

The Storage permission is needed only for exporting or importing events from .ics files.

The Contacts permission is used only at importing contact birthdays and anniversaries.

This app is just one piece of a bigger series of apps. You can find the rest of them at www.simplemobiletools.com
From version Simple Calendar 3.4.2:
Hide public notification content if desired so (by fraang)
Added optional grid on the monthly view
Allow exporting events on SD cards
Allow selecting No Sound as a reminder sound
Set default event status for CalDAV events as Confirmed
All versions
April 13, 2018