📅Dates
Date tools handle calendar calculations: difference between dates, business days, exact age, holidays, time zones and countdowns. Useful for deadlines, planning and any situation where counting days by hand invites mistakes.
72 tools
Lunar Calendar
Shows the 4 main moon phases (new, first quarter, full, last quarter) for an entire month with exact dates.
Age Calculator
Calculates exact age in years, months, days and total in hours/minutes/seconds from a birth date.
Day Counter
Counts days between two dates (including or excluding weekends). Also computes weeks, months and full years.
Countdown
Live countdown to a date and time. Updates every second showing remaining days, hours, minutes and seconds.
Season
Shows the current season (summer, autumn, winter, spring) in the Southern or Northern Hemisphere for any date.
Week & Day of Year
For any date, computes the ISO 8601 week number, day of year (1-366) and the quarter.
Moon Phase
Computes the current moon phase (new, waxing, full, waning) and the illumination percentage for any date.
Brazilian Holidays
Lists Brazilian national holidays (including movable: Carnival, Easter, Good Friday, Corpus Christi) for any year between 1900 and 2100.
Date Difference Calculator
Calculate the difference in days, weeks, months and years between two dates. Instant result in the browser.
Add Days to Date
Calculate the resulting date when adding N days to a start date. Instant result with correct leap year handling.
Subtract Days from Date
Calculate the resulting date when subtracting N days from a date. Instant result with correct leap year handling.
Calendar with Brazilian Holidays
View all 12 months in one page with Brazilian national holidays highlighted. Navigate between years and check fixed and movable holidays.
Time Lived Calculator
Discover exactly how long you have lived: years, months, days, hours and weeks since your date of birth.
Business Days Calculator
Calculate the number of business days (Monday to Friday) between two dates. Shows total days, business days and weekends.
Age on Other Planets
See how old you would be on Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto — based on each planet orbital period. Everything in your browser.
Next Birthday Countdown
How many days, hours, minutes and seconds until your next birthday? Also shows which day of the week it falls on. Everything in your browser.
Leap Year Checker
Check whether a year is leap following Gregorian calendar rules (divisible by 4, except non-400 centuries). Lists the next N. Everything in your browser.
Retirement Countdown (BR)
Estimate years until retirement under post-Reform rules: minimum age and contribution time (men/women). Everything in your browser.
Western Zodiac
Show Western zodiac sign for a given date.
Chinese Zodiac
Compute Chinese zodiac sign from year.
Easter Date (any year)
Compute Christian Easter date for any year (Gauss/Anonymous algorithm).
ISO Week Number
Compute ISO 8601 week number (1-53) for any date. Weeks start Monday; week 1 contains the first Thursday of the year.
Working Days Until Date
Compute how many working days (Mon-Fri) until a date. Option: subtract Brazilian national holidays.
Days Until Christmas
Count days until next Christmas (Dec 25) — in calendar days, working days (BR) and hours. Live updates.
Carnival Date (any year)
Compute Carnival Tuesday (47 days before Easter) for any year, plus surrounding days.
Brazilian Junina Festas Dates
Show Brazilian Junina festas dates for a year and weekday of each.
Julian Day Number
Compute Julian Day (JD) — continuous day count from January 1, 4713 BC. Standard in astronomy and geophysics.
ISO Week from Date (Complete)
Find the ISO 8601 week number (1 to 53) and the weekday of any date. Useful for reports, planning, systems and schedules that use ISO weeks.
Brazilian Folk Festivals
Calendar of Brazil's main folk festivals.
Moon Phases (Month Chart)
Find out the Moon phase on any date: New, Waxing, Full or Waning. Useful for fishing, gardening, astronomy, night photography and fun facts.
Longest Night of the Year
Winter solstice in each hemisphere.
Shortest Night of the Year
Summer solstice in each hemisphere.
Japanese Calendar Date (Wareki)
Convert a full Gregorian date to the Japanese calendar, with the right era — Meiji, Taisho, Showa, Heisei or Reiwa — the year within that era and the Japanese spelling.
Thai Buddhist Calendar Date
Convert a full Gregorian date to the Thai Buddhist calendar (543 years ahead), with the date written in Thai script, the weekday and flags for the 1889 and 1941 reforms.
Korean Calendar Year (Dangi Era)
Find the year in the Dangi era, counted from the legendary founding of Gojoseon in 2333 BC: add 2333 to the Gregorian year. 2026 is Dangi 4359.
Vietnamese Calendar Year (Can Chi)
Find the year name in the Vietnamese sexagenary cycle, with its heavenly stem, earthly branch and zodiac animal: 2026 is Bính Ngọ, the year of the Horse.
Business Days Calculator (Brazil)
Counts business days between two dates, skipping weekends and Brazil's fixed national holidays. Movable dates such as Carnival are not counted.
Friday the 13th Finder
Find every Friday the 13th in any year and see which months they fall on. A fun look at the unlucky superstition day to plan around (or laugh at).
Next Friday the 13th
Find out when the next Friday the 13th is from today and how many days are left. A fun look at the superstition day to plan around (or just for kicks).
Upcoming Eclipses
See the list of upcoming solar and lunar eclipses with date and type. Plan your viewing of these astronomical events and find out which ones are visible.
Gregorian to Hijri Date Converter
Converts a Gregorian date into the Islamic Hijri calendar with day, month name and year AH, using the tabular civil reckoning built into your browser.
Gestational Age Calculator (LMP)
Calculate gestational age in weeks and days from the last menstrual period (LMP). Track the pregnancy week by week with precision.
Due Date Calculator (Naegele)
Calculate the estimated due date (EDD) using Naegele's rule from the last menstrual period. Track the pregnancy and find out when the baby is expected.
Days Until 18 (Legal Age)
Find out exactly how many days are left until you (or someone) turns 18 and reaches legal adulthood. Enter a birth date and see the precise countdown.
Next Leap Year Finder
Find the next leap year from any given year and understand the rule behind February 29. Useful for planning, fun facts and calendars.
Japanese Era (Nengō) Converter
Convert a Gregorian year into the Japanese imperial era (Reiwa, Heisei, Shōwa and more). Useful for documents, history and anyone studying Japanese culture.
Gregorian to Persian Calendar Converter
Convert any date to the Persian (Solar Hijri, or Jalali) calendar, with the month name, weekday, Persian-Indic digits and how far the date sits from Nowruz.
Day of the Week Finder
Find out what day of the week any date fell on (or will fall on), from year 1 to 9999. Great for your birth day, historical dates and future events.
Ordinal Day of Year
Return the ordinal day number in the year (1 to 365/366) and how many days are left until year-end. Useful in meteorology and agriculture.
Akan Day Name
Return the Akan day name (West African system, Ghana) based on the day of week. Babies are given the day-name of their birth (e.g. Kofi = Friday).
Star Trek Stardate
Convert Earth date to Star Trek TNG-era Stardate (1000 units per year, baselined to 2323). Geek fun with the official TNG-era formula.
Hebrew Calendar Converter
Convert a Gregorian date to the Hebrew (Jewish) calendar. Useful for religious holidays, bar mitzvahs, anniversaries and dates in Judaism.
Islamic Hijri Converter
Convert a Gregorian date to the Islamic (Hijri) calendar. Useful for tracking Ramadan, religious holidays and dates across the Muslim world.
Persian Jalali Converter
Convert a Gregorian date to the Persian (Jalali) calendar, used officially in Iran and Afghanistan. Useful for travel, documents and study.
Bengali Calendar Converter
Convert a Gregorian date to the Bengali (Bangabda) calendar, used in Bangladesh and India. Useful for cultural dates, festivals and study.
Indian Saka Converter
Convert a Gregorian date to the Saka calendar, the official national calendar of India. Useful for cultural dates, documents and study.
Coptic Calendar Converter
Convert a Gregorian date to the Coptic calendar, used by the Coptic Orthodox Church of Egypt. Useful for liturgical dates, religious holidays and study.
Ethiopian Calendar Converter
Convert a Gregorian date to the Ethiopian (Ge'ez) calendar, which has 13 months and runs about 7 to 8 years behind. Useful for travel and study.
French Republican Converter
Convert a Gregorian date to the French Republican calendar, used during the French Revolution (1792-1806). A historical curiosity and study tool.
Next Full Moon
Find the date of the next Full Moon from today and how many days are left. Useful for planning night photography, fishing, gardening, rituals and stargazing.