What your result means
The number counts calendar days from January 1, which is 1. December 31 is 365, or 366 in a leap year. For the date you pick, the result also shows the days left in the year, the share of the year counted through that date, and the weekday. Enter a number instead and you get its date. The numbers follow the Gregorian calendar, so from March 1 on, every date in 2028 has a number one higher than the same date in 2026.
How to use the Day of the Year Calculator
- Leave the date as it is to see the number for the date on your device.
- Or pick another date, such as a due date or a shipping date.
- Read the number, the days left, the share of the year counted through that date, and the weekday.
- To go backwards, choose "Date from a day number", then enter a number such as 200 and a year.
- Use Copy link to save or share the date.
Formula and worked example
number = days in the earlier months + date of the monthleft = days in the year − numbershare = number ÷ days in the year × 100Leap year: add 1 for dates from March 1 on.
Worked example: the months before November 2026 add up to 304 days, and 304 plus 7 is day 311 of 365 for Saturday, November 7, 2026. That leaves 54 days. The share of the year counted through that date is 311 divided by 365, which is 85.2%.
Near midnight, the number depends on where you are
Two people can see different numbers at the same moment, because the date changes at midnight in each time zone. At 11:30 p.m. on Saturday, November 7, 2026 in Los Angeles, it is 4:30 p.m. on Sunday, November 8 in Tokyo. The first date is day 311 and the second is 312.
The calculator uses the date on your device. The page itself cannot know your time zone before your browser runs, so the number printed in the page is for the date it was built, in UTC, and your browser replaces it with your own date.
Day number of the first of each month (2026 and 2028)
| Month | 2026 | 2028 (leap year) |
|---|---|---|
| January | 1 | 1 |
| February | 32 | 32 |
| March | 60 | 61 |
| April | 91 | 92 |
| May | 121 | 122 |
| June | 152 | 153 |
| July | 182 | 183 |
| August | 213 | 214 |
| September | 244 | 245 |
| October | 274 | 275 |
| November | 305 | 306 |
| December | 335 | 336 |
| December 31 | 365 | 366 |
The table gives the day number of the first of every month in 2026, a common year, and in 2028, a leap year. The calculator works for any year from 1900 to 2200.
Assumptions and limits
- Dates use the Gregorian calendar. Leap years (every 4 years, except century years not divisible by 400) are handled.
- The numbers count whole calendar days from January 1. No time of day is involved.
- The calculator uses the date and time zone of your device once it runs in your browser.
Frequently asked questions
What number day of the year is it today?
It depends on the date on your device, which the calculator reads in your browser. For a fixed example, Saturday, November 7, 2026 is day 311 of 365. January 1 is 1 and December 31 is 365, or 366 in a leap year. If the number looks off by one near midnight, check your device's clock and time zone.
What year and day is it?
The result gives the number, such as day 311 of 365, with the weekday, the days left and the share of the year counted. The working below it names the full date, for example Saturday, November 7, 2026. The weekday and year come from the date on your device. The count starts at January 1 of that year.
How do I find the day number of a date?
Add up the days in all the months before it, then add the day of the month. For November 7, 2026, January through October add up to 304, and 304 plus 7 is 311. You can also take the table's number for the first of the month, 305 for November, and add 6.
Does a leap year change the day numbers?
Yes, for every date from March 1 on. March 1 is number 61 in 2028, a leap year, and 60 in 2026. January and February have the same numbers in both years, except that 2028 has a February 29, which is 60. A year is a leap year if it divides by 4, except century years, which must divide by 400, so 2000 and 2028 are leap years and 2100 is not. The extra day keeps the calendar in step with the seasons, because the solar year is about 365.2422 days long.
How many days are left in the year?
Subtract the number from 365, or from 366 in a leap year. On November 7, 2026, number 311, that leaves 54 days. The share of the year counted through that date is 311 divided by 365, which is 85.2%.
How do I turn a day number into a date?
Count forward from January 1 of that year, which is 1. Number 200 falls on July 19 in 2026 and on July 18 in 2028, because of February 29. Choose "Date from a day number", enter the number and the year, and the date and weekday appear.
Is a Julian date the same as the day of the year?
Sometimes. Some older programs and spreadsheets call the year plus the day number a "Julian date", although the preferred name is ordinal date, and ISO 8601 writes it as 2026-311. In a two-digit-year code, 26311 would mean number 311 of 2026, which is November 7. The Julian day number used in astronomy is a different system. Ask whoever supplied a code which one they mean before you convert it.
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About this calculator
Written and maintained by Ahsan Khan. See how every number is calculated, and the test cases checked on every update, on the methodology page.
Sources
- Leap Year, Hong Kong Observatory (accessed Nov 7, 2026)
- Which years are leap years and can you have leap seconds?, Royal Museums Greenwich (accessed Nov 7, 2026)
- Ordinal date, Wikipedia (accessed Nov 7, 2026)
- SPICE Time Subsystem (Required Reading), NASA JPL Navigation and Ancillary Information Facility (accessed Nov 10, 2026)
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