Everything is worked out in your browser and saved on this device for next time.
About the day of the week calculator
Which day of the week were you born? Was your wedding on a Saturday? What day will 1 January be in 2030? Pick a date and this calculator tells you the day of the week, the full date, the day of the year, the week number, and whether it is a leap year. It also shows how many days ago or from now the date is.
For a birthday or an anniversary you also get the next time the date comes round, the days until then, and the age you turn. A table shows which weekday the date falls on in each coming year — useful to plan a party.
How to use it
- Pick a date
- Read the day of the week
- See the day of the year, the week number and the leap year
- Check the table for the weekday in the next 10, 20 or 50 years — change it with Show the next
Example
15 June 1990 was a Friday. It was day 166 of the year, in week 24, and 1990 was not a leap year.
What weekday is 1 January?
| Year | 1 January |
|---|---|
| 2024 | Monday |
| 2025 | Wednesday |
| 2026 | Thursday |
| 2027 | Friday |
| 2028 | Saturday |
| 2029 | Monday |
| 2030 | Tuesday |
| 2031 | Wednesday |
A normal year has 365 days = 52 weeks + 1 day, so a date moves one weekday later each year. After a leap year (366 days), it moves two.
Friday the 13th
| Year | Months with a Friday the 13th |
|---|---|
| 2026 | February, March, November |
| 2027 | August |
| 2028 | October |
Every year has at least one Friday the 13th, and at most three.
How it works
The calculator uses the calendar built into your browser, so it works for dates in the past and the future — the Gregorian calendar that most of the world uses today. For dates before 1582 (when it was introduced), old calendars gave other weekdays, so the result is not historical.
By hand, a classic way is Zeller's rule or the Doomsday rule by John Conway.
Frequently asked questions
What day of the week was I born?
Pick your date of birth. The first line of the result is the day.
What day will my birthday be next year?
The table at the bottom lists the weekday of your birthday for each coming year.
What is the ISO week number?
The ISO week starts on Monday, and week 1 is the week with the first Thursday of the year. It is used in many countries for work and school plans.
Why are the day-of-year numbers different in leap years?
After 29 February the numbers move up by one. For example 1 March is day 60 in a normal year and day 61 in a leap year.
What about 29 February?
The table shows only the years that have a 29 February.
Does it work for any year?
Yes, within the range of your browser's dates. For years before 1582 the result follows today's calendar and may not match old documents.
Good to know
- Your date is saved only in this browser
- Names follow your language
- Nothing you type is sent anywhere
Related tools
- Age Calculator — exact age in years, months and days
- Date Calculator — add days or find the days between dates
- Countdown to Date — count down to your birthday
- Zodiac Sign Calculator — your star sign
- Printable Calendar — print a calendar for the year
