How to find the day of the week for a date
- Pick the Date you want to check. It starts on today.
- Read the day of the week, and how many days ago or ahead the date is.
- Below that you’ll find the day of the year, the ISO week number and whether the year is a leap year.
Why your birthday moves each year
A normal year has 365 days, which is 52 weeks and 1 day. So a date falls one weekday later each year. A leap year adds 29 February, and any date after it jumps two weekdays.
| Year | 17 May falls on |
|---|---|
| 2026 | Sunday |
| 2027 | Monday |
| 2028 | Wednesday (leap year) |
| 2029 | Thursday |
The same calendar repeats every 28 years, as long as the span doesn’t cross a century year that skips its leap day, such as 2100.
Working it out in your head
The doomsday rule makes this quick. In any given year these dates all share one weekday: 4/4, 6/6, 8/8, 10/10 and 12/12, plus 9 May, 5 September, 11 July, 7 November and the last day of February. In 2026 they all fall on a Saturday, and in 2027 on a Sunday.
To find the weekday of any 2026 date, count from the nearest of those. Christmas Day is 13 days after Saturday 12 December, which is 1 week and 6 days, so it lands on a Friday. Checking a date like this by hand takes a few seconds once the anchor dates are familiar.