Day of Year Calculator
Find the day number for any date, see how much of the year is complete, and check how many days remain before year end.
Selected Date
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Day of Year
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Days Passed
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Days Remaining
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Year Length
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Leap Year Status
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Year Progress
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Choose a date to calculate the day number in the year.
How to Use This Tool
- Pick any date from the date input or use the quick example buttons.
- Read the day number, days remaining, year length, and leap year status.
- Use the progress bar to see how far through the year the selected date sits.
What This Page Answers
- What day number is this date in the year?
- How many days are left in the year?
- Is the selected year a leap year?
- What percentage of the year is complete?
Frequently Asked Questions
How do I calculate the day of year for a date?
Pick a date and the calculator counts how many days have elapsed since January 1, including leap year adjustments automatically.
Does leap year change the day number?
Yes. In leap years, dates after February 29 are shifted by one day compared with common years because the year contains 366 days instead of 365.
How are days left in the year calculated?
Days left in the year are calculated by subtracting the selected day number from the total number of days in that year.
What is year progress?
Year progress is the percentage of the calendar year completed as of the selected date, based on either 365 or 366 total days.