Time & Date calculators
Free professional time & date calculators with verified formulas and step-by-step solutions.
30 Day Calculator
Find any date N days from or before a start date. Choose calendar days or Monday–Friday business days. Common presets: 30, 60, 90, 120, 180,…
Open90 Day Calculator
Find any date 90 days from or before a start date. Calendar days (the legal default) or business days. Common deadline ranges with quick pre…
OpenDays Between Dates Calculator
Count the days, weeks, months, and business days between any two dates. Handles leap years, the inclusive-vs-exclusive question, and Monday-…
OpenNumber of Days Calculator
Find how many days are in any year or month, which day of the year a date is, days remaining in the year, and whether the year is a leap yea…
OpenBirth Year Calculator
Work out the year you were born from your current age. Because birthdays do not all land on January 1, the result is always a pair of years …
OpenWeek Number Calculator
What week of the year is it? Switch between ISO 8601 (Monday start, the international standard) and US (Sunday start, Excel default). Second…
Open6 Month Calculator
Calculate the date 6 months from or before any start date. Calendar or business days. Quick presets for 1, 3, 6, 9 and 12 months.
OpenYears Between Dates Calculator
Find the exact span between two dates in years, months, and days, plus decimal years, total months, weeks, and days. The same tool works as …
Open180 Day Calculator
Find any date 180 days from or before a start date. Calendar days (the legal default) or business days. Built for Schengen 90/180, IRS 183-d…
OpenTime Until Calculator
Live countdown calculator. Enter any future date (and optional time) - see exactly how long until it, refreshed every second.
Open45 Day Calculator
Find any date 45 days from or before a start date. Calendar days (the legal default) or business days. Common deadlines: NET 45 invoices, IR…
OpenAge Calculator
Calculate exact age from a date of birth. Returns years-months-days, total days lived, day of the week you were born, days to next birthday,…
Open60 Day Calculator
Find any date 60 days from or before a start date. Calendar days (the legal default) or business days. Common deadline ranges with quick pre…
OpenDate of Birth Calculator
Reverse age calculator: enter a current age and reference date to get the date-of-birth range. Includes birth year, generation, Chinese zodi…
OpenMonth Counter Calculator
Count the exact number of full months between any two dates, with a year-month-day breakdown plus decimal months, total weeks, and total day…
OpenWorking Days Calculator
Calculate working days (Monday-Friday) between any two dates, with optional US federal holiday exclusion. Shows working days, calendar days,…
Open120 Day Calculator
Find any date 120 days from or before a start date. Calendar days (the legal default) or business days. Handy for visa rules, probation peri…
OpenAdd Time Calculator
Add or subtract a duration in hours, minutes, and seconds to/from a start time. Shows the result in both 24-hour and 12-hour formats, plus d…
OpenGraduation Year Calculator
Enter your current grade level (K-12 or college year) and the calculator returns your high school graduation year (Class of YYYY) plus the s…
OpenDate Countdown Calculator
A live date countdown calculator. Pick any target date (and optional time) and see exactly how long until it — in full calendar breakd…
Open100 Day Calculator
Find any date 100 days from or before a start date. Calendar days or business days. 100 days = 14 weeks and 2 days, about 3.3 months.
Open30 Minute Time Calculator
Enter any start time and see what time it will be in 30 minutes, an hour, 90 minutes, and 2 hours, plus 30 minutes ago. The calculator handl…
OpenBirthday Calculator
Enter your birth date to get exact age (years/months/days), countdown to next birthday, day of the week you were born, Western and Chinese z…
OpenAge Difference Calculator
Age difference calculator between two birthdates. Enter each person's date of birth and get the age gap in years, months and days, total day…
OpenDays Until December Calculator
Days until December calculator. Defaults to today and rolls over to next year automatically when the target has already passed. Shows the da…
OpenDays Until Christmas Calculator
Live countdown to Christmas Day (December 25). Shows days, hours, minutes and seconds remaining, weeks until Christmas, percentage of the ye…
OpenCountdown Calculator
Live countdown to any future date and time. Enter a target date with an optional time (defaults to midnight) and the countdown calculator ti…
OpenBirthday Countdown Calculator
Live birthday countdown: see exactly how many days, hours, minutes, and seconds remain until your next birthday. Handles leap-day births (Fe…
OpenAge in Years Calculator
Calculate your age in precise decimal years (for example, 25.34 years) from a date of birth. The calculator also returns total days, weeks, …
OpenTime Calculator
Two modes in one calculator. Difference: enter a start and an end clock time (24-hour), get the elapsed h:m:s, decimal hours, total minutes,…
OpenAge in Years, Months, and Days
Get a precise breakdown of your age in years, months, and days - accurate to a single day, accounting for leap years and variable month leng…
OpenDay of the Year Calculator
Day of the year calculator: enter a date and get the ordinal day number (Jan 1 = 1, Dec 31 = 365 or 366), the number of days remaining in th…
OpenMinute Calculator
Convert minutes to seconds, hours, days, and weeks, or do clock arithmetic by adding or subtracting minutes from a time. Output covers 24-ho…
OpenTime Adder Calculator
Add and subtract a list of time durations in HH:MM:SS format. The time adder calculator handles video editing splits, timesheets, training l…
OpenAge to Birthday Calculator
From a birth date, the calculator returns exact age in years, months, and days; the live countdown to your next birthday; total days and hou…
OpenDays Until Valentine's Day Calculator
Live countdown to the next February 14. Total days, weeks, hours, minutes, and seconds plus the day of the week Valentine's Day falls on thi…
OpenHow Old Was I Calculator
Enter your date of birth and a past event date - 9/11, your wedding, the moon landing, anything - and see exactly how old you were in years,…
OpenDay Counter Calculator
Count days between two dates and convert the result to weeks, months, years, and business days. Toggle inclusive or exclusive end-date count…
Open8 Hour Shift Calculator
Enter your shift start time and lunch length, and the 8 hour shift calculator returns your end time, the halfway point, suggested lunch star…
OpenHours and Minutes Calculator
Convert between hours and minutes and decimal hours, then add or subtract two time values. Useful for timesheet calculations, payroll math, …
OpenBaby Age Calculator
Track your baby's age in weeks for the first 12 weeks, in months until 24 months, and in years after that. Includes adjusted (corrected) age…
OpenBC to AD Calculator
Count the years between any BC and AD date with the no-year-zero adjustment built in. The calculator switches between BC/AD and BCE/CE notat…
OpenLunar Age Calculator
Lunar age calculator that converts a Gregorian birthdate to Chinese lunar age (虚岁) or East Asian nominal age. The Chinese reckoning starts a…
OpenDays Until June Calculator
Days until June calculator. Defaults to today and rolls over to next year automatically when June has already passed. Shows the day count, w…
OpenBusiness Days Calculator
Count Monday-Friday business days between any two dates, or add a number of business days to a start date. Optional US federal holiday exclu…
OpenMonths Between Dates Calculator
Find the number of months between any two dates. Returns full months plus the remaining days, decimal months for fractional spans, and a com…
OpenTime Between Dates Calculator
Calculate the time between two dates (with optional times) as a full breakdown: years, months, days, hours, and minutes. Also returns decima…
OpenAge in Weeks Calculator
Calculate your age in weeks from a date of birth. Output covers total weeks plus remainder days, decimal weeks, total days, calendar age, an…
OpenElapsed Time Calculator (Hours, Minutes, Seconds)
Enter two clock times (HH:MM:SS) and read the elapsed time as H:M:S, readable hours and minutes, decimal hours, total minutes, and total sec…
OpenTime Difference Calculator (With Time Zones)
Enter two clock times and optional IANA time zones to get the real elapsed time plus the clock difference and the time-zone offset separatel…
OpenNew Year's Countdown Calculator
Live countdown timer to Jan 1 in your local timezone. Updates every second. Includes the global timezone window — Kiribati (UTC+14) ce…
OpenAge in Days Calculator
Calculate your exact age in days from a birthdate. Plus total hours, minutes, seconds, week-day of birth, leap days lived through, and the d…
OpenHour Countdown Calculator
A live countdown to a target time and date, optimized for horizons from minutes to a few days. Pick the target with the date and time inputs…
OpenDate Calculator
Multi-mode date calculator. Find days between two dates, add or subtract days from a date, or display today with weekday, ISO date, and Juli…
OpenClock Duration Calculator
Find the duration between two clock times. Pick 12-hour AM/PM or 24-hour format. Automatically handles overnight shifts that cross midnight.
OpenLeap Year Calculator
Check whether a given year is a leap year using the Gregorian 4/100/400 rule. Shows days in year, the next and previous leap years, and a tr…
OpenExpiration Date Calculator
Expiration date calculator that turns a production date plus a shelf life (in days, weeks, months or years) into the exact expiry date with …
OpenKorean Age Calculator
Convert birthdate to Korean traditional age (1 at birth, +1 each January 1), Western international age, and Korean year age (yeon-nai).
OpenHours Calculator
Multi-mode hours calculator. Compute hours and minutes between two clock times (with optional break), add or subtract durations, and convert…
OpenDate to Date Calculator
Calculate the duration between two dates. Returns calendar Y/M/D breakdown plus total days, weeks, months, years, and business days. Auto-sw…
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