Day of the Week Finder
Find out what day of the week any date falls on, plus its day-of-year (1–366) and whether it is a weekend.
Saturday
It is the 1st Saturday of January 2000.
January 2000 has 5 Saturdays. January 2000 has 31 days. 2000 has 366 days.
| Sun | Mon | Tue | Wed | Thu | Fri | Sat |
|---|---|---|---|---|---|---|
| ISO 8601 | 2000-01-01 | |
|---|---|---|
| ISO week date | 1999-W52-6 | |
| Ordinal date | 2000-001 | |
| Month first (US) | 01/01/2000 | |
| Day first | 01/01/2000 | |
| Written out | 1 January 2000 |
Which weekday, which day of the year
Pick any date and this tool instantly tells you which day of the week it falls on — Sunday through Saturday — spelled out in full. It also shows the day of the year (1 for January 1, up to 365 or 366 in a leap year) and flags whether the date lands on a weekend. It answers questions like "what day of the week was I born?", "what day was our anniversary?", or "is this future deadline a Saturday?". Choose a date with the picker and every value updates immediately.
How the day of the week is calculated
The weekday is derived directly from the calendar date using the same proleptic Gregorian rules your operating system uses, so it stays correct for dates far in the past and future. Leap years are handled automatically, which is why the day-of-year count reaches 366 in years like 2024 and 2020 but stops at 365 in common years. Because the whole calculation happens locally, you can look up birthdays, historical events, and upcoming dates as many times as you like — everything runs in your browser, so your dates never leave your device.
Frequently asked questions
What day of the week was I born on?
Enter your birth date in the picker and the tool immediately shows the full weekday name — for example, January 1 2000 was a Saturday. It also tells you the day of the year you were born and whether it was a weekend.
Does it handle leap years correctly?
Yes. The weekday and day-of-year use the standard Gregorian calendar with full leap-year rules, so February 29 is recognised and the day-of-year count reaches 366 in leap years such as 2024, but 365 in common years.
Does it say which Monday of the month it is?
Yes. Besides the weekday it says which one of the month it is and whether it is the last, how many of that weekday the month has, the ISO week, the quarter, and how long the month and the year are.
Can I see the whole month, or the date in other formats and languages?
Yes. Under the answer, a calendar of the month marks the date, and every other day in it is a button that answers for that day. “The same date, written other ways” gives ISO 8601, the ISO week date, the ordinal date, month first (US), day first and written out, each with its own copy button. “Also name it in” adds the weekday's name in another language.
Does it tell me the zodiac sign or the moon phase of a date?
Not on this page — each has a tool of its own, the zodiac sign finder and the moon phase calculator, both linked from this one. This page keeps to calendar facts: the weekday, its place in the month, the day of the year, the ISO week and the quarter. A date's “planetary association” or “character” is astrology, not a calendar fact, so it is left out.