Dev: Add Zeller's Congruence utility class to calculate the day of the week#6614

DenizAltunkapan merged 7 commits intoTheAlgorithms:masterTheAlgorithms/Java:masterfrom

BanulaKumarage:feature/add-zellers-congruenceBanulaKumarage/Java:feature/add-zellers-congruenceCopy head branch name to clipboard