We propose a modification of a key component in the Doomsday Algorithm for calculating the day of the week of any calendar date. In particular, we propose to replace the calculation of the required term: \lfloor \frac{ x}{ 12} \rfloor + x \bmod 12 + \lfloor \frac{ x \bmod 12}{ 4} \rfloor with the term 2y + 10 \, (y \bmod 2) + z + \lfloor \frac{ 2 \, (y \bmod 2) + z}{ 4} \rfloor where x is an input 2-digit year; y is the tens digit of x; z is the ones digit of x; We argue the fact that our modification operates on individual base-10 digits makes the algorithm easier to calculate mentally.
Categories: cs.DS cs.DM