Weekday Calculator

Find out what day of the week any date falls on. Perfect for historical research, planning, and satisfying your curiosity about dates.

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About Weekday Calculations

How It Works

The weekday calculation uses mathematical algorithms to determine the day of the week for any given date. The most common method is based on Zeller's congruence or similar formulas that account for leap years and calendar variations.

Interesting Facts
  • January 1, 2000 was a Saturday
  • Your birthday moves forward 1 day each year
  • Leap years add an extra day shift
  • The Gregorian calendar was adopted in 1582
  • Friday the 13th occurs 1-3 times per year
  • February 29 only exists in leap years
  • The pattern repeats every 400 years
  • Monday is the most common birthday
Uses
  • Historical research and genealogy
  • Event planning and scheduling
  • Academic and educational purposes
  • Curiosity about special dates
  • Trivia and fun facts