Date Fraction Calculator
Express a date as a decimal year.
Calculate a date as a fraction of the year in decimal. Free date-to-year-fraction converter.
Calculator Inputs
About Fraction of Year
Express a date as a decimal year.
Converts a calendar date to continuous decimal-year notation.
Where it is used
Astronomy, scientific data, financial time-value.
How to use the Fraction of Year
- Date β enter the value.
- Calculate β press the Calculate button to see the result instantly above.
Formula
year + (dayOfYear - 1) / daysInYear
Examples
Example
date:2026-07-02
Result: ~2026.5 decimal
Frequently Asked Questions
- Why decimal year?
- For continuous math on dates (rates, curves).