Run the whole method on one date: what day was 6 June 1944 (D-Day)?

Tuesday.

1. Century anchor (1900s) = Wednesday (3).
2. Year's doomsday for 44: q = 3, r = 8, s = 2 → 3 + 3 + 8 + 2 = 16, mod 7 = 2 = Tuesday.
3. The date: June's doomsday date is 6/6, which is the doomsday. 6 June = 6/6 → Tuesday.

Check: D-Day, 6 June 1944, was a Tuesday. ✓ Three small steps — anchor, year, date — and you're done.