1) open calendar settings -> account -> sync -> according to my use
2) go back and notice if first account option is grayed (sync in progress)
3) close completely app (not simply tab back key)
4) go to phone settings and check if calendar is allowed in background
5) then, unpin e repin the tile on start. Some seconds or some minutes, it starts
I use Simple Calendar, have for a few years now. It's free and looks good in wide tile. It displays the Month, Day, Year, and up to three daily calendar, or tasks.
They still haven't got this sorted. The fix is simple enough, though:
Input a "fake" calendar event for today's date. Exit and the tile should show that event. Go back into the program and delete that event. The date should now be on the tile.