Day of the Week Calculator - Find What Day Any Date Falls On

Find what day of the week any date falls on. Free weekday calculator for historical dates and future planning.

Date Finder

Historical Range:

This calculator works for dates from 1900 to 2100, covering most historical and future planning needs.

Day Information

Select a date to find the day of the week

About Day of the Week Calculator

The day of the week calculator helps you determine what day any specific date falls on. This is useful for historical research, event planning, scheduling, and general curiosity about dates in the past or future.

Common Uses

  • Historical Research: Find what day historical events occurred
  • Event Planning: Check what day of the week future dates fall on
  • Personal Interest: Discover what day you were born on
  • Business Planning: Determine weekdays vs weekends for scheduling
  • Academic Research: Date verification for historical studies
  • Genealogy: Research family history and important dates

How It Works

The calculator uses mathematical algorithms to determine the day of the week for any given date. It accounts for leap years, calendar reforms, and the Gregorian calendar system used in most of the world.

Interesting Date Facts

  • The Gregorian calendar was adopted in 1582, replacing the Julian calendar
  • Leap years occur every 4 years, except for years divisible by 100 (unless also divisible by 400)
  • The day of the week pattern repeats every 400 years
  • January 1, 2000 was a Saturday
  • The 13th of any month is slightly more likely to fall on a Friday

Calendar Systems

This calculator uses the Gregorian calendar, which is the most widely used calendar system today. Different cultures and religions may use other calendar systems for specific purposes.