Date and Time Calculators
Count calendar days, plan working time, and compare clocks around the world.
Date & Time tools
Age Calculator
Find calendar age in years, months, days, and total days.
Date & TimeDate Difference Calculator
Count days and weeks between two calendar dates.
Date & TimeTime Duration Calculator
Calculate elapsed hours and minutes, including overnight periods.
Date & TimeBusiness Days Calculator
Count Monday–Friday working days with optional holiday exclusions.
Date & TimeTime Zone Difference Calculator
Compare two IANA time zones at a specific UTC instant, including daylight saving.
Date & TimeWork Hours Calculator
Calculate paid time and gross pay after unpaid breaks.
Date & TimeBirth Year Calculator
Find your possible birth years from a completed age and reference date, or use birthday information to narrow the answer.
Date & TimeRecommended calculators
Calendar dates, elapsed time, and world clocks
Age gives calendar years, months, and days; Date Difference counts or offsets calendar dates. Time Duration compares clocks or UTC instants, and Work Hours totals shifts with unpaid breaks. Business Days supports custom weekends and holidays. Time Zone Difference compares locations using a UTC instant or a source-local date and time.
Do daylight saving changes affect every date tool?
Date-only tools compare calendar dates without daylight saving shifts. Clock-duration modes use wall-clock time; explicitly labeled UTC date-time modes count instants. Time Zone Difference applies the selected IANA zone rules and explains the input convention.