Home & Life
Date & Time Calculators
Age, days between dates, working days, hours and time zones. Free calculators with formulas and worked examples.
Dates
Age CalculatorFind your exact age in years, months and days, how many days you have lived, and how long until your next birthday.Date CalculatorAdd time to a date, take time away from it, or find how many days lie between two dates.Working Days CalculatorCount the working days between two dates, skipping weekends and any public holidays you enter. Choose the weekend pattern used…Days Until ChristmasSee exactly how long it is until Christmas Day, counted from today or from any date you choose.
Time
Time Zone ConverterFind out what time it will be somewhere else. Pick a date and time in one place and see the local time in another, with…Unix Timestamp Converter (Epoch Time to Date)Convert epoch time to a human date, or a date to a Unix timestamp.Military Time Converter (24-Hour to 12-Hour)Enter a time in either format to see it in the other.Time Duration Calculator (Between Two Dates and Times)Enter a start and end date and time to get the duration.Decimal Hours Converter (Hours and Minutes to Decimal)Convert time worked between hours:minutes and decimal hours.Time CalculatorAdd up time cards, video lengths or cooking times in one go.Hours Worked CalculatorFill in your shift times and see paid hours and earnings.
Calendar
Day of the Week Calculator (What Day Was It?)Pick any date to see which day of the week it falls on.Week Number Calculator (ISO 8601)Find which week of the year a date falls in, or the start and end of any week number.Day of the Year Calculator (Day Number)Pick a date to see its day number and how much of the year is left.Leap Year CalculatorEnter a year to see if it is a leap year and when the next one is.Countdown Calculator (Days Until a Date)Pick an event date to see exactly how long is left.Birthday Calculator (Next Birthday and Countdown)Enter your date of birth to count down to your next birthday.Add Business Days Calculator (Date After N Working Days)Enter a start date and a number of working days to find the due date.Julian Date Converter (JD, MJD and Day Number)Convert between calendar dates and Julian Day numbers used in astronomy and satellite work.Easter Date Calculator (Western and Orthodox)Enter a year to find Easter Sunday and the dates that depend on it.Moon Phase Calculator (Phase and Illumination by Date)Pick a date to see the Moon's approximate phase and when the next full moon is.Retirement Date CalculatorEnter your date of birth and retirement age to find your retirement date.
Date differences
Birthdays
Calendars
About these calculators
Count days, weeks and working days between dates, find your exact age, add or subtract time, convert time zones and total up hours worked. Dates use the Gregorian calendar.
Each calculator explains its formula, includes a worked example and lists its sources. Read how we check them on our editorial policy page, or browse all calculators.
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Please note: TheCalcTools gives general estimates for information and education. It is not financial, medical, legal or tax advice, and results should be checked before you make a decision. See our disclaimer and about page.