Abstract

• Congruence can be used to determine on which day of the week a given date falls. We discuss the calendar formula to calculate the day of the week of December 25, 2017. Also, we express easier formula to calculate. And then, we describe Conways Doomsday Algorithm. The Doomsday Algorithm is an Algorithm for calculating the day of the week for any given calendar date. The algorithm is based on first computing doomsday which is the day of the week of the last day of February, or of January. We present an acceleration method for calculating the dooms year term of the Doomsday algorithm. Finally, we show that simple acceleration method is similar in form to Conways lookup table acceleration method