🗓️ Day of the Week Finder

Enter any date to find out what day of the week it falls (or fell) on.

Date

How this tool finds the day of the week

Every calendar date maps to exactly one day of the week, following the modern Gregorian calendar that most of the world uses. This tool uses your browser's built-in date engine to look up that mapping instantly for any date — whether it's decades in the past or years in the future — without you needing to count weeks by hand or consult a paper calendar.

Why this is useful

Historical records, old photographs, and legal documents often list only a date, not a day of the week. Knowing the day can help verify a date is correct, add context to a historical event, or simply satisfy curiosity about which weekday a birthday or anniversary lands on in a given year.

Worked example: July 4, 1776 — the day the U.S. Declaration of Independence was adopted — fell on a Thursday. Meanwhile, January 1, 2030 falls on a Tuesday.

Common uses

Verifying historical datesCross-check that a listed date and weekday in an old document actually match.

Planning recurring eventsConfirm which weekday a specific date falls on before scheduling something weekly.

Trivia & curiosityFind out what day of the week you were born, or what day a future date will be.

Genealogy researchAdd weekday context to birth, marriage, or death records.

Frequently asked questions

How far back or forward does this work?

The tool works for any date supported by your browser's date system, which generally covers a very wide range of years — centuries in both directions — using the standard Gregorian calendar.

Does it account for calendar changes (e.g., the switch from Julian to Gregorian)?

No — it always applies the modern Gregorian calendar. For dates before the Gregorian calendar was adopted in a given country (commonly the 1500s–1700s), the actual historical weekday may differ.

Why does my birthday fall on a different weekday most years?

Because a regular year has 365 days — exactly 52 weeks plus 1 day — your birthday shifts forward by one weekday each year, except across leap years when it shifts by two.