Date & Time Tools
Calculate ages and the time between dates, add or subtract days, months and years, count working days, convert time zones and Unix timestamps, and use a countdown timer, stopwatch or world clock.
21 tools
- Age CalculatorCalculate exact age in years, months and days from a date of birth — plus total days, weeks and your next birthday.
- Days Between Dates CalculatorCount the days, weeks, months and years between two dates, with weekdays and an option to include the end date.
- Date Calculator (Add or Subtract Days)Add or subtract days, weeks, months and years to or from any date.
- Sleep CalculatorFind the best time to go to bed or wake up, in 90-minute sleep cycles, so you wake between cycles rather than in deep sleep.
- Time Zone ConverterConvert a date and time between any two time zones, with daylight saving handled for you.
- Countdown TimerA simple online countdown timer with presets, alarm sound and full-screen display.
- Hijri Date ConverterConvert Gregorian dates to Hijri (Islamic) dates and back, on the Umm al-Qura calendar, with the weekday.
- StopwatchAn online stopwatch with lap times, accurate to hundredths of a second.
- Unix Timestamp ConverterConvert Unix epoch timestamps to dates and back, in seconds or milliseconds.
- Working Days CalculatorCount business days between two dates, excluding weekends and your public holidays.
- Time CalculatorAdd and subtract hours, minutes and seconds, and convert the total to decimal hours.
- World ClockSee the current time in cities around the world, and add your own.
- Hours Calculator (Time Between Two Times)Calculate hours worked between a start and end time, minus breaks, including overnight shifts.
- Week Number CalculatorFind the ISO week number for any date, with the week’s start and end dates.
- Add Business DaysFind the date that is a given number of business days (weekdays) after or before a date.
- Time Unit ConverterConvert seconds, minutes, hours, days, weeks, months and years.
- Add or Subtract MonthsAdd or subtract calendar months from a date, handling month ends correctly.
- Add or Subtract YearsAdd or subtract years from a date, including leap-day handling.
- Leap Year CalculatorCheck whether a year is a leap year and find the next and previous leap years.
- Contract End Date CalculatorWork out when a contract or lease ends and the last day to give notice.
- Jet Lag CalculatorSee the time difference for your trip, which way your body clock has to shift and simple tips to adjust faster.