All calculators
Seven exact date calculators. Every one shows the calendar rule it applies.
Age calculator
Exact age in years, months and days — plus your next birthday.
Date difference calculator
Exact days, weeks and months between any two dates.
Add or subtract days calculator
Add or subtract days, weeks, months or years.
Countdown calculator
Days until (or since) any date, in both directions.
Business days calculator
Monday–Friday count between two dates.
Day of week calculator
The weekday of any date, past or future.
Leap year checker
Is a year a leap year? The rule, applied.