you don't have to "open" this calendar: just go to the list of available widgets in your device, find calendar widgets there and drop it to the screen.
Don't forget that you can resize it.
Features:
* Synced with your calendars
* Shows markers for dates with events
* Automatically updates when you add/delete/modify an even
* Indicators for alerts and recurring events
* Shows today's agenda
* Opens default calendar app by taping on event
* Beautiful and clean design
* Customize colors of the widget background and texts
The widget is based on open source and We will constantly improve its functionality to make it more useful.