Date & Time Calculators

15 free date and time calculators for age, date math, countdowns, time zones, and more. No signup required.

15 free tools

Age Calculator

Calculate your exact age in years, months, and days from your birthdate. See total days lived and next birthday.

Date Difference Calculator

Find the exact number of days, weeks, months, and years between any two dates.

Add or Subtract Days from a Date

Add or subtract days, weeks, or months from any date to find the resulting date.

Days Until Calculator

Count down to any future date. See days, weeks, months, and hours until your event.

Day of Week Calculator

Find out what day of the week any date falls on — past or future.

Business Days Calculator

Count working days between two dates, excluding weekends. See weekend days and total days too.

Time Duration Calculator

Calculate the hours, minutes, and seconds between two times of day.

Hours Calculator

Add or subtract hours and minutes. Find total time for timesheets or work schedules.

Week Number Calculator

Find the ISO week number for any date. See what week of the year any date falls in.

Unix Timestamp Converter

Convert Unix timestamps to human-readable dates and back. Supports seconds and milliseconds.

Sleep Calculator

Find the best bedtimes or wake times based on 90-minute sleep cycles for optimal rest.

Time Zone Converter

Convert a time from one time zone to another using UTC offsets.

Leap Year Calculator

Check whether any year is a leap year and see the nearest past and future leap years.

Military Time Converter

Convert between 12-hour and 24-hour (military) time formats instantly.

Day of Year Calculator

Find the day number (1-365) for any date and see how many days remain in the year.