Day of Year Calculator
Find the day number (1-366), days remaining and percentage of year elapsed for any date.
Results
What day of the year is June 15? It is day 166 (or 167 in a leap year). This calculator converts any date to its ordinal day number within the year. Farmers use it for planting windows, meteorologists for weather records, astronomers for Julian dates and logistics teams for delivery scheduling. Enter any date to see the day number, remaining days, year progress percentage and fiscal quarter.
Explore all our date and calendar calculator tools, or browse the full time and date converters & calculators.
Frequently asked questions
Enter today's date to see the exact day number. January 1 = day 1, February 1 = day 32, July 1 = day 182 (or 183 in a leap year), December 31 = day 365 or 366.
Farmers reference 'growing degree days' and planting schedules by day of year. Corn planting in the US Midwest targets days 110-140 (mid-April to late May). Day numbers avoid confusion across month boundaries.
Julian Day Number (JDN) is a different concept - a continuous count of days since January 1, 4713 BC. Our Julian Day Converter handles JDN. Day of year (ordinal date) counts from January 1 of the same year.
Add the day number minus 1 to January 1. Day 100 of 2025 = January 1 + 99 days = April 10, 2025. Use our Add or Subtract Days calculator for quick conversion.
Yes. Leap years have 366 days, with February 29 as day 60. All dates from March 1 onward shift by one day compared to non-leap years.