Date and time

Calculate calendar spans, weekdays, clock durations and timezone conversions.

• Age Calculator

  Calculate exact calendar age and elapsed days on a chosen date.

• Date Difference Calculator

  Find elapsed days and the calendar span between two dates.

• Date Add or Subtract Calculator

  Add or subtract days, weeks, months or years from a calendar date.

• Business Days Calculator

  Count Monday-to-Friday days between two dates, excluding dates you enter.

• Time Duration Calculator

  Find elapsed clock time across midnight and subtract a break.

• Hours and Minutes Calculator

  Add or subtract two durations in hours and minutes.

• Day of the Week Calculator

  Find the weekday, day of year and ISO week for any Gregorian date.

• Time Zone Converter

  Convert a local date and time between named IANA time zones.

• Time Calculator

  Add, subtract, multiply or divide durations in hours, minutes and seconds, or move a clock time forward or back across midnight.

• Time to Decimal Calculator

  Convert hours, minutes and seconds to decimal hours and decimal minutes for a timesheet, or turn decimal hours back into hours, minutes and seconds.

• Week Number Calculator

  Find the week number of any date, ISO 8601 or Sunday-start, with the first and last day of that week, or find the dates of a given week number.

• Dog Age Calculator

  Convert a dog’s age to human years with the DNA-methylation formula from a 2020 study of Labrador retrievers, not the one-to-seven rule.

• Sleep Calculator

  Work out a bedtime from the time you need to wake, or a wake-up time from when you go to bed, using your own cycle length and time to fall asleep.

• Moon Phase Calculator

  Find the moon's phase and age on any date from 1900 to 2100, and when the next full moon and new moon fall, in your own UTC offset.

• Hijri Date Converter

  Convert a Gregorian date to the Islamic (Hijri) calendar and back, by Saudi Arabia’s Umm al-Qura calendar or the 30-year arithmetic calendar.

• Hebrew Date Converter

  Convert a Gregorian date to the Hebrew (Jewish) calendar and back, with the weekday and whether the Hebrew year is a leap year.

• Persian Calendar Converter

  Convert a Gregorian date to the Persian (Solar Hijri, Shamsi) calendar used in Iran and Afghanistan, and back, from 1925 to 2123.

• Ethiopian Calendar Converter

  Convert a Gregorian date to the Ethiopian calendar and back, with its thirteenth month, Pagume, and the seven or eight year gap.

• Indian National Calendar Converter

  Convert a Gregorian date to the Indian national calendar (Saka era) and back, with the Vikram Samvat year.

• Easter Date Calculator

  Find the date of Easter Sunday for any year from 1583 to 4099, Western and Orthodox, with Ash Wednesday, Good Friday, Ascension and Pentecost.

• Japanese Era Calculator

  Convert a date or a Western year to the Japanese era year (Reiwa, Heisei, Shōwa, Taishō, Meiji) and back, with the kanji and the day each era changed.

• Korean Age Calculator

  Work out international age, the traditional Korean counting age and the year age used in some Korean laws, from a date of birth.

• Buddhist Era Calculator

  Convert between the Buddhist Era (BE) used in Thailand and Sri Lanka and the Common Era (CE), including Thailand’s pre-1941 April New Year.

• Chinese Zodiac Calculator

  Find your Chinese zodiac animal and element from your date of birth, using the actual Lunar New Year date for that year, 1901 to 2100.

• Nepali Date Converter

  Convert an English (AD) date to the Nepali Bikram Sambat (BS) calendar and back, from 2000 BS (1943) to 2087 BS (2031).