What Day of the Year Is It?
What day of the year is it? On October 26, 2026, the date this calculator is served with, it is day 299 of 365, with 66 days left in the year, in ISO week 44. In your browser the date fills in with today's date from your device, so the answer is for today. Pick any other date to look it up.
Day of the year
- Day of the year January 1 is day 1. 2026 is a common year of 365 days.
- 299 of 365
- Days left in 2026 After October 26, 2026, through December 31. Counting October 26, 2026 itself, 67.
- 66
- Share of the year done 299 รท 365, at the end of the day.
- 81.9%
- ISO week number Monday October 26, 2026 to Sunday November 1, 2026. ISO weeks start on Monday, and week 1 is the week with the year's first Thursday in it.
- Week 44
- ISO week-numbering year The same as the calendar year. It differs only for a few days around January 1.
- 2026
- Weeks in that ISO year 2026 has 53 ISO weeks, as every year does that starts on a Thursday, or is a leap year starting on a Wednesday.
- 53
- ISO week date Year, week and weekday, with Monday as 1. Monday is 1.
- 2026-W44-1
- ISO ordinal date Year and day of the year. The day-of-year Julian date code for the same day is 26299.
- 2026-299
- Quarter
- Q4
| Month | Day number of the 1st | Day number of the last day |
|---|---|---|
| January | 1 | 31 |
| February | 32 | 59 |
| March | 60 | 90 |
| April | 91 | 120 |
| May | 121 | 151 |
| June | 152 | 181 |
| July | 182 | 212 |
| August | 213 | 243 |
| September | 244 | 273 |
| October | 274 | 304 |
| November | 305 | 334 |
| December | 335 | 365 |
- The date field fills in with your device's local date when the calculator loads. The page itself is generated in advance, so the answer it is served with is for the fixed example date.
- Spreadsheet WEEKNUM functions default to another system, where week 1 is the week containing January 1 and weeks start on Sunday, so their number can differ from the ISO week by one. The ISO number is the one written in a YYYY-Www date.
How the Julian Date Converter works
The day of the year counts from January 1 as day 1 to December 31 as day 365, or 366 in a leap year. October 26, 2026 is day 299: 273 days in January through September, plus 26. That leaves 66 days in 2026 after it, or 67 counting October 26 itself, and the year is 81.9% done by the end of that day.
Leap years move everything after February by one. In 2028, March 1 is day 61, where in a common year such as 2026 it is day 60. The table under the result lists the day number of the first and last day of every month for the year of the date you pick, so a day number can be read off for any date in that year.
The week of the year is a separate count, and the international standard for it is ISO 8601. Its weeks run Monday to Sunday, and week 1 is the week that contains the year's first Thursday, which is the same as the week containing January 4. October 26, 2026 is a Monday and opens week 44, written 2026-W44-1 as an ISO week date.
Because week 1 is fixed by a Thursday, the first and last few days of a calendar year can belong to the neighboring year's weeks. 2026 began on a Thursday, so its week 1 started on Monday, December 29, 2025, and that Monday is 2026-W01-1. The same rule gives 2026 a 53rd week, which runs into January 2027: January 1, 2027 is a Friday in week 53 of 2026, written 2026-W53-5. A year has 53 ISO weeks when it starts on a Thursday, or when it is a leap year that starts on a Wednesday; every other year has 52. The ISO week-numbering year is the year a date's week belongs to, and it is the one to use with a week number.
Spreadsheet WEEKNUM functions default to a different system, where week 1 is the week containing January 1 and weeks start on Sunday. Their number can be one more than the ISO week, so check which one a schedule or a report uses. In a spreadsheet, the ISO number comes from ISOWEEKNUM.
The day number is also the last three digits of a day-of-year Julian date code: October 26, 2026 is 26299 in the five-digit form and 2026299 in the seven-digit one. Switch the mode to convert a code back to a date. The day of the year calculator takes any date from the year 100 onward, counted on the Gregorian calendar.
Julian Date Converter FAQ
What day of the year is it today?
The calculator fills in today's date from your device when it loads and gives the day number for it. The example it is served with is October 26, 2026, which is day 299 of 365, with 66 days left.
What week of the year is it?
By ISO 8601, the week containing the year's first Thursday is week 1 and weeks start on Monday. October 26, 2026 is the Monday that starts week 44. The calculator shows the ISO week for whichever date is entered.
How many weeks are in 2026?
53 ISO weeks, because 2026 starts on a Thursday. Week 1 began on Monday, December 29, 2025, and week 53 ends on Sunday, January 3, 2027.
How do I find the day number of a date?
Add the lengths of the months before it, then the day of the month. October 26 is 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 = 273, plus 26, so day 299 in a common year and day 300 in a leap year.