Date and Age Calculator
Calculate the difference between two dates, add or subtract time from a date, or work out an exact age.
Runs entirely in your browser.
Date Difference, Date Math and Age Tool
About Date Calculations
Date calculations account for the varying lengths of months and for leap years, which add an extra day every four years (with a century exception). Counting the difference between two dates in calendar years, months, and days is more involved than simply dividing the total number of days.
This tool computes precise differences, performs date arithmetic such as adding business-relevant amounts of time, and determines an exact age along with the number of days until the next birthday. All calculations run entirely in your browser.
Single-Purpose Date Tools
This page has all three tabs. If you only need one answer:
- Age Calculator — exact age and days to the next birthday
- Date Difference — the span between two dates
- Add or Subtract Days — date arithmetic
- Leap Year Checker — is a year a leap year, and why
- Day of the Week — weekday, day of year and ISO week
