What is the newest version to write in graddle? Because I doubt it is 1.0.0.

[BumblebeeTF]

Like in topic.

[DBXJes]

There are also more versions.
Just use the next version like this one:
implementation 'com.github.SpongeBobSun:mCalendarView:Tag' Referenced by Github version.

Or use the Maven repository.
implementation group: 'sun.bob', name: 'mcalendarview', version: '1.1.0'