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Date & Time
Browse 51 working calculators for date & time. Every tool shows a live result, its calculation steps, and the sources behind the method.
Datetime
51 calculators
Age as CalculatorAge in completed years, months and days on any date, with the total days lived, the weekday of birth, the next birthday and the gap between two birth dates; it also runs backwards to recover a date of birth from an age, breaks an age down into every time unit, and corrects an infant age for prematurity. Age counts completed calendar months and days, so a 29 February birth attains the next year of age on 1 March in common years.Age Conversion CalculatorAge in completed years, months and days on any date, with the total days lived, the weekday of birth, the next birthday and the gap between two birth dates; it also runs backwards to recover a date of birth from an age, breaks an age down into every time unit, and corrects an infant age for prematurity. Age counts completed calendar months and days, so a 29 February birth attains the next year of age on 1 March in common years.Date as CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Hours & Time CalculatorElapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos, halving or splitting a duration, and rescaling a runtime for playback speed.Timer CalculatorTime remaining until a target date and time - days, hours, minutes and seconds, plus the calendar breakdown - and the finish time of a timer of a given duration.Day Countdown CalculatorTime remaining until a target date and time - days, hours, minutes and seconds, plus the calendar breakdown - and the finish time of a timer of a given duration.Birth Date Year CalculatorAge in completed years, months and days on any date, with the total days lived, the weekday of birth, the next birthday and the gap between two birth dates; it also runs backwards to recover a date of birth from an age, breaks an age down into every time unit, and corrects an infant age for prematurity. Age counts completed calendar months and days, so a 29 February birth attains the next year of age on 1 March in common years.Snow Day CalculatorScores the chance of a snow-day school closure from a forecast you supply - snowfall against the local NWS warning criterion, ice accretion, NWS wind chill and the timing of the storm.Time Zone CalculatorConverts a date and time between time zones using the IANA rules in force on that date, plans a meeting across several zones at once, and re-times a fixed dosing schedule after travel.Dates Times CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Business Day CalculatorCounts working days between two dates, adds or subtracts a number of working days from a date, and rolls a deadline forward to the next working day under the Rule 6(a) convention.Calendaring CalculatorCounts working days between two dates, adds or subtracts a number of working days from a date, and rolls a deadline forward to the next working day under the Rule 6(a) convention.Dog Age CalculatorConverts a dog or cat’s age into human-equivalent years using the AVMA/AAHA staged model by size, or the Wang (2020) canine epigenetic clock, and reports the life stage that age falls into.Payday CalculatorLists the coming paydays for a weekly, biweekly, semimonthly or monthly pay schedule, with the next payday and the days until it. Weekly and biweekly schedules run on a fixed 7- or 14-day cycle from a known payday (26 biweekly pay dates a year, not 24); semimonthly and monthly schedules use fixed days of the month, clamped to the month end when the month is short. A payday landing on a weekend or federal holiday is moved to the preceding business day by default, which is the common US employer practice.Epoch CalculatorConverts a Unix timestamp in seconds, milliseconds, microseconds or nanoseconds into a UTC date and time, and converts a date and time back into a timestamp. Unix time counts seconds since 1970-01-01T00:00:00Z with every day exactly 86400 seconds long (POSIX ignores leap seconds), so the conversion is exact integer arithmetic and independent of the reader’s time zone.Age Expectancy CalculatorRemaining and total life expectancy at your current age from the published US period life table, with survival probabilities to later ages and an optional adjustment for smoking, weight, activity and alcohol using published years-of-life effects.Birthday Day CalculatorThe weekday any date falls on, with the hand working (Zeller’s congruence), the day of the year, the days left in the year, the quarter, the ISO week and the ISO week-numbering year, which is not always the calendar year. In birth-date mode it also lists the weekday of the coming anniversaries.Employment Time CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Add Times CalculatorElapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos, halving or splitting a duration, and rescaling a runtime for playback speed.Asq CalculatorAge in completed years, months and days on any date, with the total days lived, the weekday of birth, the next birthday and the gap between two birth dates; it also runs backwards to recover a date of birth from an age, breaks an age down into every time unit, and corrects an infant age for prematurity. Age counts completed calendar months and days, so a 29 February birth attains the next year of age on 1 March in common years.Day Since CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Day Till CalculatorTime remaining until a target date and time - days, hours, minutes and seconds, plus the calendar breakdown - and the finish time of a timer of a given duration.Hrs Minutes CalculatorElapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos, halving or splitting a duration, and rescaling a runtime for playback speed.Julian Date CalculatorConverts between a calendar date and the astronomical Julian Day (a continuous day count from -4712-01-01 12:00 UT, so JD 2451545.0 is 2000-01-01 12:00 UT), the Modified Julian Date, and the ordinal "Julian date" stamp used on manufactured goods and in the military (24061 = day 61 of 2024). It runs in both directions and also gives the Julian-calendar equivalent of the date.Time Decimal CalculatorConverts a length of time between clock form (h:mm:ss) and decimal hours, minutes, seconds and days, in either direction: 90 minutes is 1 hour 30 minutes and 1.5 decimal hours, and 7:45 on a timesheet is 7.75 hours. Conversions are the exact SI-accepted ones (1 h = 3600 s), and a two-part value such as 7:45 is read as hours and minutes or as minutes and seconds according to the chosen reading.Time Half CalculatorElapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos, halving or splitting a duration, and rescaling a runtime for playback speed.Age Difference CalculatorAge in completed years, months and days on any date, with the total days lived, the weekday of birth, the next birthday and the gap between two birth dates; it also runs backwards to recover a date of birth from an age, breaks an age down into every time unit, and corrects an infant age for prematurity. Age counts completed calendar months and days, so a 29 February birth attains the next year of age on 1 March in common years.Daily Calendar CalculatorAdds or subtracts years, months, weeks and days from a date and reports the date it lands on, with its weekday, day of the year and ISO week. Years and months are applied before weeks and days, a month step that overshoots the month end is clamped to the last day of that month (31 January + 1 month = 29 February in 2024), and days are counted exclusively - the start date is day 0 - unless the inclusive basis is chosen.UTC Est CalculatorConverts a date and time between time zones using the IANA rules in force on that date, plans a meeting across several zones at once, and re-times a fixed dosing schedule after travel.Life Expectancy Social Security CalculatorRemaining and total life expectancy at your current age from the published US period life table, with survival probabilities to later ages and an optional adjustment for smoking, weight, activity and alcohol using published years-of-life effects.Minute Time CalculatorConverts a length of time between clock form (h:mm:ss) and decimal hours, minutes, seconds and days, in either direction: 90 minutes is 1 hour 30 minutes and 1.5 decimal hours, and 7:45 on a timesheet is 7.75 hours. Conversions are the exact SI-accepted ones (1 h = 3600 s), and a two-part value such as 7:45 is read as hours and minutes or as minutes and seconds according to the chosen reading.Month CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Time Into Minutes CalculatorConverts a length of time between clock form (h:mm:ss) and decimal hours, minutes, seconds and days, in either direction: 90 minutes is 1 hour 30 minutes and 1.5 decimal hours, and 7:45 on a timesheet is 7.75 hours. Conversions are the exact SI-accepted ones (1 h = 3600 s), and a two-part value such as 7:45 is read as hours and minutes or as minutes and seconds according to the chosen reading.Week CalculatorThe week of the year a date falls in, under ISO 8601 numbering (Monday-start weeks, week 1 holds the first Thursday, so the week-numbering year can differ from the calendar year) or US/Excel WEEKNUM numbering (Sunday-start weeks, week 1 holds 1 January). It also runs backwards, giving the start and end dates of a given week number, and reports how many weeks the year has.Day Into Year CalculatorThe weekday any date falls on, with the hand working (Zeller’s congruence), the day of the year, the days left in the year, the quarter, the ISO week and the ISO week-numbering year, which is not always the calendar year. In birth-date mode it also lists the weekday of the coming anniversaries.Half Birthday CalculatorThe date half a year from a birthday, the weekday it falls on, and the days until it. The calendar reading adds six months and clamps a non-existent day to the month end (31 August gives 28 February, or 29 in a leap year); the alternative adds half the days of the year, 182 or 183. The half birthday reported is the next one on or after the reference date.Hebrew Calendar CalculatorConverts a Gregorian date to the Hebrew date and back, using the arithmetic (molad-based) Hebrew calendar with its postponement rules: seven leap years in each 19-year cycle add the month of Adar I, and Cheshvan and Kislev flex by a day so a common year runs 353-355 days and a leap year 383-385. A Hebrew day runs sunset to sunset, so the date given is the one covering the daytime of the Gregorian date.How Many Year CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Sobriety CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Sobriety Date CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Time UTC CalculatorConverts a date and time between time zones using the IANA rules in force on that date, plans a meeting across several zones at once, and re-times a fixed dosing schedule after travel.90 Day CalculatorAdds or subtracts years, months, weeks and days from a date and reports the date it lands on, with its weekday, day of the year and ISO week. Years and months are applied before weeks and days, a month step that overshoots the month end is clamped to the last day of that month (31 January + 1 month = 29 February in 2024), and days are counted exclusively - the start date is day 0 - unless the inclusive basis is chosen.Date Number CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.Time Zones Meeting Planner CalculatorConverts a date and time between time zones using the IANA rules in force on that date, plans a meeting across several zones at once, and re-times a fixed dosing schedule after travel.Calendar Maya CalculatorConverts a Gregorian date into the Maya Long Count, the 260-day Tzolk’in round (a number 1-13 with one of 20 day names) and the 365-day Haab’ year, using the Goodman-Martinez-Thompson correlation constant 584283 that places 13.0.0.0.0 on 21 December 2012. Haab’ days are numbered from 0, the seating of the month, as in the Smithsonian converter.Cat Age CalculatorConverts a dog or cat’s age into human-equivalent years using the AVMA/AAHA staged model by size, or the Wang (2020) canine epigenetic clock, and reports the life stage that age falls into.Living 100 Life Expectancy CalculatorRemaining and total life expectancy at your current age from the published US period life table, with survival probabilities to later ages and an optional adjustment for smoking, weight, activity and alcohol using published years-of-life effects.Mayan Birth Sign CalculatorConverts a Gregorian date into the Maya Long Count, the 260-day Tzolk’in round (a number 1-13 with one of 20 day names) and the 365-day Haab’ year, using the Goodman-Martinez-Thompson correlation constant 584283 that places 13.0.0.0.0 on 21 December 2012. Haab’ days are numbered from 0, the seating of the month, as in the Smithsonian converter.Time Ago CalculatorDays, weeks, months and years between two calendar dates, with the calendar breakdown, the business-day count and the weekday of each date; it also measures between two date-and-time instants, counts the time elapsed since a date up to today, reports length of service, and lists the sobriety milestones passed.CST IST Converter CalculatorConverts a date and time between time zones using the IANA rules in force on that date, plans a meeting across several zones at once, and re-times a fixed dosing schedule after travel.Subtract Time CalculatorElapsed time between two clock times, including overnight and multi-day spans, adding or subtracting hours, minutes and seconds from a time, totalling a list of durations such as a playlist or a set of videos, halving or splitting a duration, and rescaling a runtime for playback speed.