180 + 10 does not apply to the S/D. But there is absolutely no need to call day by day with just few exceptions....only CRT and Chef's Table at V&A. Even for CRT, I don't think it's always necessary anymore. I know I made a reservation for lunch in March and called several weeks after the booking window opened.
Speaking of booking windows, WDW is currently only accepting reservation up to March 22. A new reservation system is coming out one of these days.
Anyway, once the window for April opens up, your father should be able to make all his reservations with one call.
