Dates & time
236 date and time calculators: days between dates, ages, business days, deadlines, time zones, durations and calendars. Exact answers that respect leap years and weekends, free in your browser.
Gregorian epact calculator
For 2026 the Gregorian epact is 11: under the church tables the Moon is 11 days old on 1 January. Enter any date and get the epact for its year, from 1 to 30…
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Excel serial number to date
Serial 44927 is 1 January 2023, and 25569 is 1 January 1970. Paste any Excel 1900-system serial number and get the calendar date, plus the time of day from its…
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Floor datetime to a minute or second interval in UTC
16:37:52 at +02:00 on 25 July 2026 is 14:37:52 UTC, and floored to 15 minutes it becomes 14:30:00 UTC.
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Gregorian to Ethiopian date converter
Type a Gregorian date and get its Ethiopian equivalent: 1 January 2024 is 22 Tahsas 2016. The result names the month, from Meskerem to Pagumen, and says whether…
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Gregorian to Hebrew date converter
Enter a Gregorian date and get its Hebrew counterpart: 3 October 2024 is 1 Tishrei 5785. You also get the civil and the religious month number, and whether the…
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Gregorian to Hijri date converter
Enter a Gregorian date and get the tabular civil Hijri date for it, such as 24 Ramadan 1420 AH for 1 January 2000.
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Gregorian to Julian calendar date converter
Enter a Gregorian date and see how the same day is written in the Julian calendar: 7 August 2026 is 25 July, 13 days behind.
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Gregorian to Indian Saka calendar converter
Type a Gregorian date and get its place in India's official Saka calendar: 15 August 1947 is 24 Shravana 1869.
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Hijri year length calculator
Enter a Hijri year and get its exact length: 1446 AH has 354 days and sits at position 6 of the 30-year cycle, while a leap year has 355 because the last month…
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Is a weekend day?
Type one date and get a clear yes or no on whether it falls on Saturday or Sunday: 25 July 2026 is a Saturday, so it is a weekend day.
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Japanese nengo era year calculator
Find the Japanese era year for any date since 1868: 2024-06-15 is Reiwa 6 (令和6年), and switchover days are exact, so 30 April 2019 is still Heisei 31.
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List all of a weekday in a month
Pick any date and a weekday to list every matching day in that month: the Mondays of March 2024 fall on the 4th, 11th, 18th and 25th.
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Maya Calendar Round Calculator for Any Date
Enter a date and get its Maya Calendar Round: 2012-12-21 is 4 Ajaw / 3 Kankin under the GMT correlation.
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Maya Long Count from date
Turn a Gregorian date into the Maya Long Count: 2012-12-21 is 13.0.0.0.0 under the GMT correlation 584283.
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Minguo ROC to Gregorian date converter
Convert a Minguo date from the Republic of China calendar into the Gregorian calendar: 113-07-25 becomes 2024-07-25.
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Modified Julian Day to date converter
Enter a Modified Julian Day and get the UTC date and time it stands for: 51544.5 is noon on 2000-01-01, while 51544.0 is the midnight that starts that day.
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Persian Jalali to Gregorian date converter
Day 1 of month 1 of the Persian year 1400 is 21 March 2021 in the Gregorian calendar. Enter a Solar Hijri year, month and day and get the matching date, with…
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Shrove Tuesday date
Enter a year to get the date of Shrove Tuesday, or Mardi Gras: in 2026 it falls on 17 February, the day before Ash Wednesday and 47 days before Easter Sunday.
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Truncate datetime to unit
Round a date and time down to the start of its year, month, day, hour or minute in UTC: 2024-06-15T14:37:52Z truncated to the day becomes 2024-06-15T00:00:00Z.
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Week number with custom first day
Pick the day your weeks start on and get the week number of any date, with week 1 always holding 1 January: 15 March 2024 is in week 11 when weeks start on…
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Weekday of New Year's Day
New Year's Day 2026 falls on a Thursday, weekday number 4 when Monday counts as 1. Type any date and the tool tells you how its year began, which helps when you…
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Black Friday date calculator by year
Enter a year and get the US Black Friday date, the Friday right after Thanksgiving: in 2026 Thanksgiving is 26 November and Black Friday is 27 November.
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Easter Monday date
Easter Monday 2024 fell on 1 April, the day after Easter Sunday on 31 March; in 2025 it is 21 April.
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Tabular Eid al-Adha date
In Hijri year 1445, 10 Dhu al-Hijjah falls on Monday 17 June 2024 under the tabular Islamic calendar.
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US Father's Day date
In 2026, US Father's Day falls on Sunday 21 June. Enter any year to get the third Sunday of June, which always lands between 15 and 21 June, for calendar…
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Groundhog Day date and weekday calculator by year
Enter a year and see which day of the week Groundhog Day lands on: 2 February 2026 is a Monday. The date never changes, only the weekday, so this settles…
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Memorial Day date calculator
Enter a year and get the US Memorial Day date, the last Monday of May: in 2026 it falls on May 25.
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Palm Sunday date
Palm Sunday 2026 falls on 29 March, exactly seven days before Easter on 5 April. Type any year and get the Western Palm Sunday date for Holy Week calendars…
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Approximate Autumnal Equinox Date and Time Calculator
Get an estimate of the September equinox for any year from 1000 to 3000: in 2026 it falls on 23 September at 00:13:43 UTC.
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EU daylight saving start date
In 2026, EU summer time starts on Sunday 29 March, when clocks move forward one hour at 01:00 UTC.
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Approximate Holi date calculator
Enter a year and get an approximate Holi date: in 2026 the March full moon falls on 3 March at 11:38 UTC.
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Meteorological season of a date
Enter a date and a hemisphere to get its meteorological season: 2026-03-21 is spring in the north, while the same day is autumn in the south.
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Passover Start Date Calculator by Year
In 2026 Passover begins at sunset on 1 April, the evening before 15 Nisan on 2 April. Enter any year to get the start date from the fixed rules of the Hebrew…
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Rosh Hashanah date calculator
Enter a year and get the civil date of Rosh Hashanah: in 2026, 1 Tishri falls on 12 September and opens Hebrew year 5787.
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UK summer bank holiday date
Enter a year to get the date of the UK late summer bank holiday, the last Monday of August in England, Wales and Northern Ireland: in 2026 it is 31 August.
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Subtract two HMS durations
Enter two durations in hours, minutes and seconds and get the exact difference: 12:05:10 minus 03:47:55 is 08:17:15, or 29835 seconds.
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Hours minutes seconds to seconds
Enter hours, minutes and seconds and get the single total in seconds that timers and spreadsheets store: 90 minutes alone is 5400 seconds, and 2 hours is 7200.
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Total duration of time intervals
Paste a list of time intervals and get the real time they cover: 10:00 to 12:00 and 11:00 to 13:00 UTC cover 3 hours, not the 5 a plain sum gives.
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Add two ISO 8601 durations
Enter two ISO 8601 durations and get their sum as one clean duration: P1W plus P3D gives P10D, because weeks become seven days.
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Overlapping time of two intervals calculator
A 09:00 to 12:30 UTC slot and a 13:15 to 16:00 slot at UTC+02:00 share 75 minutes, or 1.25 hours. Enter the start and end of two ranges and get their exact…
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Stopwatch split times
Paste the cumulative stopwatch marks and get each lap's own duration: three splits ending at 100 seconds become laps of 30, 35 and 35.
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Clock time to decimal minutes
Turn a clock time into minutes past midnight: 06:15:30 becomes 375.5 decimal minutes. Enter the hour, minute and second in 24-hour time and the seconds are…
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Working hours between two datetimes
A ticket opened at 15:00 UTC on Friday, July 24, 2026 and closed at 11:30 on Monday, July 27 took 4.5 working hours, or 270 minutes.
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Age in total weeks
Count how many complete weeks someone has lived between a birth date and a later day: from 15 May 1990 to 15 May 2024 is 1,774 weeks plus 1 day.
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Weekday of a birthday in any year
Find which day of the week a birthday falls on in the year you choose: someone born on 17 May 1990 has their 2030 birthday on a Friday.
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Hours difference between UTC offsets
From UTC+05:30 to UTC-04:00 the difference is -9.5 hours, or -570 minutes. Enter two fixed offsets and get the signed gap, the second minus the first, with no…
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Pregnancy week from last period
With a last period that began on 1 January 2026, on 12 March 2026 the pregnancy is 10 weeks and 0 days, first trimester, due around 8 October 2026.
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Retirement date from birthdate
Born on 15 June 1964 with a retirement age of 67? Your eligibility date is 15 June 2031. Enter a birth date and the age your plan sets to get the exact…
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Timesheet hours total
Add up worked hours from clock-in and clock-out times minus unpaid breaks: two shifts of 09:00 to 17:30 and 09:15 to 17:00, with 30 and 45 minute breaks, give…
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Convert time between UTC offsets
14:30 at UTC+2 is 07:30 at UTC−5: the same instant written on the other side's clock. Enter a date and time and two fixed offsets to get the destination time…
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Day fraction to clock time
0.75 of a day is 18:00:00, and 0.5213541666666667 is 12:30:45. Enter a fraction from 0 to 1 and get the clock time in hours, minutes and seconds, rounded to the…
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Length of daylight calculator by date and latitude
On 21 June 2026 at latitude 51.5074 there are about 16.6396 hours of daylight. Enter a date and a latitude to estimate how long the Sun stays above the horizon…
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GMT offset label formatter
Enter an offset in whole minutes and get wording you can show people: 120 becomes GMT plus two, 330 becomes GMT plus five hours thirty minutes and zero becomes…
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JavaScript timestamp to ISO 8601 converter
Paste a JavaScript timestamp in milliseconds and get the exact UTC date and time: 0 becomes 1970-01-01T00:00:00.000Z.
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Swatch Internet Time
Turn any date and time into Swatch Internet Time: 11:00 UTC is @500.00, noon in Biel. The day has 1000 beats of 86.4 seconds each, counted from midnight in Biel…
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Unix seconds to ISO 8601
Paste a Unix timestamp in seconds and get the exact UTC date and time in ISO 8601: 1800000000 becomes 2027-01-15T08:00:00Z.
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Approximate equation of time
On 11 February 2024, day 42 of the year, a sundial runs about fourteen and a half minutes behind a mean clock.
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Moon age in days calculator for any date
On 25 July 2026 the Moon is about 10 days old, counted from the previous new moon. Enter any date and see where it sits in the lunar cycle, a steady estimate…
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Age in years, months and days calculator
Get an exact age in whole years, months and days between a birth date and a day you choose: someone born on 15 May 1990 is 36 years, 2 months and 10 days old on…
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Age in Total Seconds Calculator
Turn the span from a birth date to a reference date into one exact count of seconds: from 1 January 2000 to 1 January 2025 is 9,132 days, or 789,004,800…
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