Day of the Year Calculator (Day Number)
Day of the year calculator: the day number (1–366) of any date, days left in the year and the share of the year that has passed.
day = date − Jan 1 + 1
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
January 1 is day 1; December 31 is day 365, or 366 in a leap year. Also called the ordinal or “Julian” day in logistics.
Frequently asked questions
Day number of December 31, 2024?
Day 366 (2024 is a leap year).
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