It's a sample of the app with CrunchyCalendar Library integrated.
A light, powerful and easy to use Calendar Widget with a number out of the box features:
Infinite vertical scrolling in both directions;
Setting date boundaries to restrict scrolling inside of a specific time period;
Single / multiple / range dates selection;
Displaying color indicators;
Setting own custom ItemDecoration;
Presented as a View subclass which can be displayed everywhere: in Activity, Fragment or Dialog, or can be integrated into another custom View.