Time & Date Calculators

Date calculators handle the fiddly parts of calendar arithmetic — leap years, months of different lengths, and inclusive versus exclusive counting — so you get the same answer a careful manual count would produce.

All date math is done on calendar dates (UTC), so results do not shift with your time zone. Where a counting convention matters (for example, whether the end date is included), the calculator states which convention it uses.

• Age CalculatorCalculate an exact age in years, months, and days between a date of birth and any date.
• Date Difference CalculatorCount the days, weeks, months, and years between two calendar dates.
• Date Add / Subtract CalculatorAdd or subtract years, months, weeks, and days from any date.
• Business Days CalculatorCount working days (Monday–Friday) between two dates, excluding weekends.