Instantly find out what day of the week any date falls on, whether in the past or the future.
This tool finds which day of the week any given date fell on, or will fall on — past, present, or future. It's useful for verifying historical dates, checking what day a future event lands on, confirming birthdays, or satisfying simple curiosity about a specific date in history.
The calculator uses the rules of the Gregorian calendar, the calendar system used internationally today, accounting for leap years (which occur every 4 years, except century years not divisible by 400) to accurately determine the weekday for any date.
Enter any date, and the tool instantly returns the day of the week it corresponds to.
Example 1: January 1, 2000 fell on a Saturday.
Example 2: July 4, 1776 (US Independence Day) fell on a Thursday.
Does this work for dates before the Gregorian calendar was adopted? The tool calculates using the modern Gregorian calendar. Countries adopted the Gregorian calendar at different times (Britain and its colonies in 1752, for example), so very old historical dates recorded in the Julian calendar may show a different weekday than the original historical record.
Why does the day of the week repeat every 7 years sometimes and not others? Because of leap years, the same date shifts by one weekday each normal year and by two weekdays across a leap year, so the pattern isn't perfectly regular.
Can I use this to plan future events? Yes, it's commonly used to check what day of the week a future date, like an anniversary or deadline, will fall on.
Is a leap year accounted for automatically? Yes, the calculation automatically applies leap year rules for any year you enter.
How far into the future or past can I check? The calculation works for any calendar date, though for dates before widespread Gregorian adoption, historical calendar differences should be kept in mind.