Algorithms Zeller’s Congruence Zeller's Congruence is a mathematical algorithm devised by Christian Zeller to calculate the day of the week for any date in both the Julian and Gregorian calendars.
System Design Strategy Design Pattern in Software Design [Java] The Strategy Pattern is a behavioral design pattern that falls under the Gang of Four's (GoF) design patterns. It provides a systematic way to define a family of algorithms, encapsulate each algorithm, and make them interchangeable.