What Day of the Week Was It?
Pick any date past or future and see exactly what weekday it falls on.
March 14, 1991 is a Thursday. The Gregorian calendar maps every date to exactly one of the seven weekdays, and the result here is computed in your local timezone.
How do you find what day of the week a date falls on?
Every date in the Gregorian calendar maps to exactly one of the seven weekdays. The calculator uses date-fns, which implements Zeller-style arithmetic accurate for any year supported by JavaScript's Date object.
Does it work for past and future dates?
Yes. Pick any date from the year 0100 through 9999 and the result is exact. Useful for checking historical events, planning future meetings, or settling a friendly bet about a birthday.
Frequently asked questions
How accurate is the result?
The calculation uses the proleptic Gregorian calendar, which is exact for any date after 1582 in countries that adopted it. For earlier dates, the result is still correct under the proleptic convention used by date-fns.
Does the day-of-week depend on timezone?
Yes, slightly. A date near midnight UTC can fall on different weekdays in different timezones. The calculator uses your local timezone.
Why does the same date of the year fall on different weekdays?
A normal year shifts every date one weekday forward year over year, and a leap year shifts by two. That's why your birthday lands on a new day each year.
Can I find the weekday of a historical event?
Yes. Try the moon landing (July 20, 1969, a Sunday) or the fall of the Berlin Wall (November 9, 1989, a Thursday).