Weekday Calculator

Calculate the day of the week for any date in history or the future

Input Parameters

Calculation Results

Result

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Calculation Formula

This calculator uses Zeller's Congruence algorithm to determine the day of the week:

h = q + floor((13(m+1))/5) + K + floor(K/4) + floor(J/4) - 2J

Where:

  • h = Day of the week (0 = Saturday, 1 = Sunday, 2 = Monday, ..., 6 = Friday)
  • q = Day of the month
  • m = Month (3 = March, 4 = April, ..., 14 = February)
  • K = Year of the century (year % 100)
  • J = Zero-based century (year / 100)

Weekday Calculator Calculator Usage Guide

Learn how to use the Weekday Calculator and understand its working principles

How to Use This Calculator

  1. Enter the year, month, and day in the input fields above.
  2. Click the "Calculate" button to determine the day of the week.
  3. The result will show which day of the week the entered date falls on.
  4. You can click "Reset" to clear all inputs and start over.

Understanding the Calculation Method

This calculator uses Zeller's Congruence, an algorithm devised by Christian Zeller to calculate the day of the week for any Julian or Gregorian calendar date. The formula takes into account the peculiarities of the calendar system and provides accurate results.

Examples of Usage

  • Check historical events that occurred on specific days
  • Plan future events by knowing which days they'll fall on
  • Verify dates in historical documents or records
  • Understand the scheduling of holidays and observances

Limitations

Zeller's Congruence works for both Julian and Gregorian calendars, but it may not be accurate for dates before the adoption of the Gregorian calendar in 1582, depending on the specific historical context.