What Day of the Year Is It?
January 1 is day 1, December 31 is day 365 (or 366). Enter any date and instantly see its ordinal day number within the year — handy for Julian date conversions, scientific records, and agricultural planning.
How to Use the Day of Year Calculator
1
Enter a date or leave it set to today.
2
The ordinal day number (1–366) is shown instantly.
3
Use it for record keeping, analysis, or conversion.
Frequently Asked Questions
What is an ordinal day number?
It is the count of days from January 1 of that year. For example, February 1 is day 32.
Does it handle leap years?
Yes. In a leap year, days after February 28 are shifted by one, and December 31 becomes day 366.
Why would I need the day of the year?
It is commonly used in astronomy, agriculture, data logging, and any field that references days by number rather than by month-day.