Since i started developing applications for android i noticed there were some undocumented apis. Google does reccomend to not use these apis but since there are no “other nice ways” to achieve some tasks sometimes they are useful ( but still unreccomended)
It’s the case of the Google Calendar Apis. Out there you can find a lot of docs about these undocumented & unsupported apis but you’ll get some troubles if google decides to change them.
For example if you want to add an “event” to the calendar programmatically you can follow the snippet below which is SDK proof. In fact i did ( It’s not refactored for better reading ) write some code that would work on Sdk from 1.5 to 2.2 ( aka Froyo ) solving the provider issue on froyo.
/**
* Adds the event to a calendar. It lets the user choose the calendar
* @param ctx Context ( Please use the application context )
* @param title title of the event
* @param dtstart Start time: The value is the number of milliseconds since Jan. 1, 1970, midnight GMT.
* @param dtend End time: The value is the number of milliseconds since Jan. 1, 1970, midnight GMT.
*/
private static void addToCalendar(Context ctx, final String title, final long dtstart, final long dtend) {
final ContentResolver cr = ctx.getContentResolver();
Cursor cursor ;
if (Integer.parseInt(Build.VERSION.SDK) == 8 )
cursor = cr.query(Uri.parse("content://com.android.calendar/calendars"), new String[]{ "_id", "displayname" }, null, null, null);
else
cursor = cr.query(Uri.parse("content://calendar/calendars"), new String[]{ "_id", "displayname" }, null, null, null);
if ( cursor.moveToFirst() ) {
final String[] calNames = new String[cursor.getCount()];
final int[] calIds = new int[cursor.getCount()];
for (int i = 0; i < calNames.length; i++) {
calIds[i] = cursor.getInt(0);
calNames[i] = cursor.getString(1);
cursor.moveToNext();
}
AlertDialog.Builder builder = new AlertDialog.Builder(ctx);
builder.setSingleChoiceItems(calNames, -1, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
ContentValues cv = new ContentValues();
cv.put("calendar_id", calIds[which]);
cv.put("title", title);
cv.put("dtstart", dtstart );
cv.put("hasAlarm", 1);
cv.put("dtend", dtend);
Uri newEvent ;
if (Integer.parseInt(Build.VERSION.SDK) == 8 )
newEvent = cr.insert(Uri.parse("content://com.android.calendar/events"), cv);
else
newEvent = cr.insert(Uri.parse("content://com.android.calendar/events"), cv);
if (newEvent != null) {
long id = Long.parseLong( newEvent.getLastPathSegment() );
ContentValues values = new ContentValues();
values.put( "event_id", id );
values.put( "method", 1 );
values.put( "minutes", 15 ); // 15 minuti
if (Integer.parseInt(Build.VERSION.SDK) == 8 )
cr.insert( Uri.parse( "content://com.android.calendar/reminders" ), values );
else
cr.insert( Uri.parse( "content://calendar/reminders" ), values );
}
dialog.cancel();
}
});
builder.create().show();
}
cursor.close();
}
Hope it helps to solve the problem about google calendar in froyo 
Reference to the CP: Xda
