Date & Time
664 free date & time calculators — including Age Calculator and Date Difference Calculator. Instant results in your browser, with the formula shown.
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Fixed Christian Feasts Calculator
Free Christian feast calculator. Find dates for fixed holidays like Christmas, Epiphany, and Annunciation for any year.
Movable Christian Feasts Calculator
Free Easter-based holy days calculator. Calculate movable Christian dates like Ash Wednesday, Pentecost, and Ascension.
Coptic Holy Days Calculator
Free Coptic holy days calculator. Find dates for fixed and movable Coptic Orthodox feasts and religious occasions.
Hebrew Holidays Calendar
Free Jewish holidays calendar. Find dates for Hebrew feasts and fasts including Rosh Hashanah, Yom Kippur, and Passover.
Holy Week Dates Calculator
Free Holy Week calculator. Find exact dates for Palm Sunday, Maundy Thursday, Good Friday, and Easter for any year.
Samaritan Calendar Converter
Free Samaritan calendar converter. Convert dates between Gregorian and Samaritan calendar systems online easily.
Samaritan Festivals Calculator
Free Samaritan festivals calculator. Find dates for religious holidays including Passover, Shavuot, and Sukkot.
Yazidi New Year Calculator
Free Yazidi New Year calculator. Find the date of Charshema Sor (Red Wednesday) and upcoming celebrations online.
Gregorian to Hijri Date Converter
Convert dates between Gregorian and Hijri calendars.
Date Difference Calculator
Calculate difference between two dates.
Age Calculator
Calculate your exact age.
Hijri to Gregorian Converter
Convert between Hijri and Gregorian dates.
Age Calculator (Years, Months, Days)
Exact age from birth date to any day, with borrow-correct months and days: born Jun 15, 1990, you are 36y 4m 1d on Oct 16, 2026. Handles leap years and Feb 29 birthdays.
Countdown Calculator
Live countdown in days, hours and minutes to any future date. Great for launches, exams and travel; works down to any date you pick, past or future.
Business Days Calculator
Counts calendar days minus weekend days, both endpoints included: Mon Oct 5 to Fri Oct 16, 2026 spans 12 calendar days and 10 business days on a Sat-Sun weekend. Fri-Sat weekend option included.
Work Days Calculator
Calculate work days between two dates (excluding weekends).
Pregnancy Week Calculator
Calculate current pregnancy week and stage.
Time Zone Converter (Offset Difference)
Convert a time across zones with one number: add the offset difference to the source time. 14:00 with a -5 h difference is 09:00, and a day indicator flags previous/next-day rollovers.
Detailed Age Calculator
Calculate your age in detail.
Advanced Sleep Cycle Calculator
Calculate optimal wake/sleep time.
Date Difference Calculator
Days between two dates, computed as end minus start in whole days: Jan 1 to Oct 16, 2026 is 288 days, about 9 months 15 days. Gives weeks, total hours and minutes too.
Day of Week Calculator
Weekday for any date, past or future, straight from the calendar: Jan 1, 2000 was a Saturday, and Oct 16, 2026 is a Friday. Also shows day-of-year and ISO week.
Lunar Age Calculator - Calculate Your Age in Hijri Calendar
Calculate your exact age in the Islamic Hijri calendar. Free lunar age calculator that shows your age in lunar years, months, and days.
Add Days to Date Calculator
Date arithmetic done on real calendar months: Oct 16, 2026 plus 45 days lands on Nov 30, 2026. Subtraction works the same way for deadlines and back-planning.
Time Duration Calculator
Elapsed time between two clock times: 09:15 to 17:45 is 8 h 30 min, or 510 minutes. Handles overnight shifts that cross midnight.
Ramadan Countdown
Calculate days remaining until next Ramadan.
Days Until Christmas Countdown
Calculate days remaining until next Christmas.
Minutes to Hours Converter
Convert minutes to hours and minutes.
Retirement Date Calculator
Adds your remaining years to your birth date: born Jun 15, 1990 and retiring at 65, your retirement date is Jun 15, 2055. Shows days remaining as well.
Date Adder
Add days, months, or years to a date.
Weekday Finder
Type any date and get its weekday instantly, e.g. Jun 15, 1990 was a Friday. Useful for verifying birthdates, receipts and historical events.
Retirement Countdown
Calculate time remaining until retirement.
Zodiac Sign Calculator
Calculate zodiac sign from birth date.
Period Cycle Calculator
Track menstrual cycle and predict next dates.
Work Hours Calculator
Calculate total work hours.
Advanced Date Difference
Calculate difference between two dates.
Islamic Hijri Date Converter
Convert between Gregorian and Hijri dates.
Unix Timestamp Converter
Convert Unix seconds to a UTC date and back: 1767225600 is Jan 1, 2026 00:00:00 UTC. Counts seconds since the epoch, Jan 1, 1970.
Hours to Days Converter
Convert hours to days, weeks, and months.
Week Number Calculator
ISO-8601 week number for any date: Oct 16, 2026 falls in week 42 of 2026. Weeks start Monday, and week 1 is the week holding the first Thursday of January.
Seconds to Hours Converter
Convert seconds to hours, minutes, and seconds.
Pay Period Calculator
Lists your next pay dates from a known anchor date and period: paid biweekly on Fridays with money landing Fri Oct 16, 2026, next cheques follow Oct 30, Nov 13, Nov 27.
Unix Epoch Converter
Convert between Unix timestamp and date.
Stopwatch Lap Calculator
Calculate lap times and splits.
Meeting Duration Calculator (Agenda Planner)
Meeting length from your agenda: items x minutes each + breaks. 8 items at 15 min with a 5-min break after every third item runs 2 h 05 m with 1 break.
Quarter Calculator
Calculate fiscal quarter and dates.
Hours Between Dates Calculator
Whole hours between two date-times: Oct 14 08:00 to Oct 16 12:00 is 52 hours. Also gives minutes and days for shift and travel planning.
Subscription Expiry Calculator
Calculate subscription expiry dates.
About Date & Time
664 free Date & Time tools are listed on this page, led by Age Calculator, Date Difference Calculator and Gregorian to Hijri Date Converter in popularity order. Each computes its result directly in your browser and shows the formula it applies. The grid also covers Hijri to Gregorian Converter, so most common Date & Time questions have a matching tool. No accounts, no fees — every answer ships with the arithmetic behind it.
What you can calculate
Age Calculator, Date Difference Calculator, Gregorian to Hijri Date Converter, Hijri to Gregorian Converter
Top Date & Time Calculators
Fixed Christian Feasts Calculator
Free Christian feast calculator. Find dates for fixed holidays like Christmas, Epiphany, and Annunciation for any year.
Movable Christian Feasts Calculator
Free Easter-based holy days calculator. Calculate movable Christian dates like Ash Wednesday, Pentecost, and Ascension.
Coptic Holy Days Calculator
Free Coptic holy days calculator. Find dates for fixed and movable Coptic Orthodox feasts and religious occasions.
Hebrew Holidays Calendar
Free Jewish holidays calendar. Find dates for Hebrew feasts and fasts including Rosh Hashanah, Yom Kippur, and Passover.
Holy Week Dates Calculator
Free Holy Week calculator. Find exact dates for Palm Sunday, Maundy Thursday, Good Friday, and Easter for any year.
FAQs about Date & Time
What is the best calculator in the Date & Time category?
The most popular Date & Time tools on this site are Age Calculator, Date Difference Calculator and Gregorian to Hijri Date Converter, in that order. All are free, run instantly in your browser, and show their calculation steps — pick the closest to your case or try more than one.
Are the Date & Time calculators free to use?
Yes — all 664 tools in the Date & Time category are completely free: they run in your browser with no sign-up and never send your inputs anywhere. Enter your values and the result appears instantly, with the formula used shown.
How many calculators are in the Date & Time category?
The Date & Time category currently lists 664 free tools. The most used are Age Calculator, Date Difference Calculator and Gregorian to Hijri Date Converter, and all of them are reachable directly from the grid on this page, with no registration required.