I need a calender control in my application to show some “appointments” in a day view. As far as I see it, there are two ways: Write my own control which would be not that funny and to use com.android.calendar.
Can anyone tell me how I can use com.android.calendar.DayView or whether at all it is possible. One important thing: I do not want to show the appointments of the user but rather my own dynamical added ones.
I am talking about this control: 
Just for information: I am aware that there are some similar questions on SO. However, I’m interested in com.adnroid.calendar.* and not as a general question :-).
That class is not in the SDK. It is undocumented. It is unsupported.
However, it is open source. You are welcome to copy it into your own project (and refactor it into your own package), but you will be on your own to figure out how to make it work.
FWIW, there is a similarly undocumented/unsupported/open source widget in the Google I|O 2011 app.
It is possible that there are other open source implementations of this sort of widget that are documented and supported, though I can’t think of any. I will probably take one of these and use it as the basis for a documented/supported widget someday, if nobody beats me to it.