Find out instantly which day of the week any date falls on — past, present, or future.
📂 Date CalculatorsFill in the fields on the left with your information, then press the button to see your result instantly. No sign-up required, and no data is sent anywhere — everything is calculated right in your browser.
This tool identifies the day of the week (Saturday, Sunday, Monday...) that corresponds to any Gregorian date you enter, whether in the past, present, or future, within any year supported by the standard Gregorian calendar. This is useful for finding out what day an upcoming event falls on (for example, confirming that an upcoming wedding date falls on a Friday), or checking the day of a past historical date (such as finding out exactly which day of the week you were born on). The tool also shows a useful extra piece of information when you choose a date in February: whether the entered year is a leap year (366 days) or a common year (365 days), using the standard leap year rule (divisible by 4, unless divisible by 100 and not divisible by 400) — the same rule adopted with the Gregorian calendar reform of 1582 and used by every modern calendar system since.
"What day of the week was I born on?" is one of the most commonly asked date-trivia questions, and it's also a genuinely practical one when you're confirming that a future event date falls where you think it does — checking, for example, that a wedding date really is a Saturday, or that a contract deadline doesn't quietly fall on a Sunday.
This calculator answers that question for any Gregorian date, past or future, instantly. Rather than counting weeks by hand from a known reference date — a method that becomes impractical and error-prone across long spans of time — it computes the day of the week directly from the date's underlying calendar mathematics, which is accurate for any date the standard Gregorian calendar can represent.
One added feature shows up specifically for dates in February: the tool tells you whether that year is a leap year, and therefore whether February has 28 or 29 days. Leap years follow a specific rule rather than a simple "every 4 years" pattern: a year is a leap year if it's divisible by 4, except that century years (like 1900 or 2100) are not leap years unless they're also divisible by 400 (which is why 2000 was a leap year but 1900 was not). This exception rule is often the part people get wrong when reasoning about leap years manually, so surfacing it directly avoids that mistake.
It's worth being precise about scope: this tool calculates using the modern (proleptic) Gregorian calendar — meaning it applies today's calendar rules consistently to any date, including dates before the Gregorian calendar was actually adopted in a given country. Historically, different countries switched from the older Julian calendar to the Gregorian calendar at different times (Britain and its colonies in 1752, for example, versus much of continental Europe in 1582), which means a specific historical date's actual recorded day of the week at the time can occasionally differ from what a purely mathematical Gregorian calculation like this one produces. For any modern date, and for the vast majority of everyday and historical uses, this distinction doesn't matter — but for calendar-history research into pre-1582 or transition-era dates, it's a useful caveat to keep in mind.
It works accurately for any date supported by the standard Gregorian calendar, covering essentially any practical past or future date.
Because whether a year is a leap year determines if February has 28 or 29 days, which is useful context when checking dates in that month.
No, this tool calculates purely using the modern (proleptic) Gregorian calendar, which is the standard used by all modern date systems and calendars.
A year is a leap year if it's divisible by 4, except that century years must also be divisible by 400 — which is why 2000 was a leap year but 1900 was not.