All Date, Time & Age Calculators
Explore our complete suite of 24 verified chronological calculators.
Age & Milestones
Age Calculator
Calculate your exact age in years, months, days, hours, and find out your next birthday countdown.
Birthday Countdown
Count down the exact days, hours, and minutes until your next birthday and see what age you will turn.
Holiday Countdown
Count down to upcoming major holidays like Christmas, New Year, Halloween, or your custom holiday.
Next Birthday Age Calculator
Find out the exact age you will turn on your next birthday, zodiac sign, and birthstone trivia.
Business & Workdays
Working Days Calculator
Count business and working days between two dates with customizable workweeks and custom holidays.
Business Days Calculator
Add or subtract a specific number of business days from a start date, skipping weekends and holidays.
Weekend Days Calculator
Count total weekend days (Saturday & Sunday or custom weekend) within any date range.
Date & Calendar Math
Date Difference Calculator
Calculate the exact elapsed time between two dates in calendar years, months, days, and total days.
Days Between Two Dates
Count total calendar days between any two dates with optional inclusive end-date counting.
Add Days to Date Calculator
Add any number of calendar days to a starting date to find the future date and day of the week.
Subtract Days From Date
Subtract days from a date to find past dates, historical milestones, and retro-timeline dates.
Week Calculator
Find the ISO-8601 week number, ISO week-year, and the start/end dates of any week.
Month Calculator
Add or subtract months from a date with explicit month-end clamping rules (e.g. Jan 31 + 1 month).
Year Difference Calculator
Calculate completed calendar years and remaining months/days between two years or dates.
Leap Year Checker
Check whether any year is a leap year according to Gregorian calendar century rules.
Day of the Week Calculator
Find the exact weekday (Monday-Sunday) for any historical, current, or future date.
Date Format Converter
Convert dates between ISO, US, UK/EU, German, Long text, and Unix timestamp formats safely.
Life Milestones & Age
Retirement Date Calculator
Calculate your estimated retirement date and remaining timeline based on your date of birth and target age.
School Admission Age Calculator
Calculate a child’s exact age on school admission cutoff dates (e.g. Sept 1 or Jan 1).
Pregnancy Due-Date Calculator
Estimate your due date, current gestational week, and trimester timeline using LMP or conception date.
Anniversary Countdown
Track your wedding or relationship milestone, upcoming anniversary countdown, and traditional gift themes.
Time & Duration
Date Duration Calculator
Calculate total duration between two dates and times in days, hours, minutes, and seconds with timezone support.
Hours Between Two Dates
Calculate elapsed hours between two date-times with daylight saving time transition awareness.
Minutes Between Two Dates
Calculate total elapsed minutes and remaining seconds between two date-time timestamps.