Well, I'm lost.
I state that the app as it is, based on the Calendar Library, with those delays of minutes, is unusable.
The question is complex (also my english is poor, as you know...!).
I have to back down: the library Calendar2 does not use Intents.
I think, I guess I understand, that there are 3 ways to use Google Calendar:
1) by commands, which operate on the Calendar Provider (this seems to be the method used by the library);
2) via Intents; but if you prepare an Intent and you start it, the application that is capable of handling this Intent installed on your device will start (ie a calendar) then I can not use this method.
3) via Sync Adapters; this method, however, requires account name and account type which I would (should?) avoid (also, it is not so simple).
All this should make me give up, but I have one more question:
If I create an event via browser on my PC it is immediately updated / synchronized with the calendar on my tablet:
so, which method it uses?
Thanks for your answers.
[P.S. BTW, trying to understand something more, I downloaded a sample (
BasicSyncAdapter) from developer.android.com then I opened it in Android Studio; for start-up of Android Studio and for loading the project, I had to wait only a few... years ]