Date arithmetic, age, countdown, and calendar tools. Browse our free date tools below — all calculators are instant, accurate, and require no sign-up.
120-Day Calculator — Calculate the exact date 120 days from any start date. Get milestones, weekday info, and monthly breakdown for 120-day planning periods.
100-Day Calculator — Calculate the exact date 100 days from any start date. Find milestones, weekday, weekly breakdown, and monthly distribution instantly.
30-Day Calculator — Calculate the exact date 30 days from any start date. Find weekday, business days, milestones, and time breakdowns for monthly planning.
180-Day Calculator — Calculate the exact date 180 days from any start date. Find the half-year mark with milestones, weekly breakdown, and monthly distribution.
45-Day Calculator — Calculate the exact date 45 days from any start date. Get business day counts, milestones, and weekday breakdowns for 45-day deadlines.
6-Month Calculator — Calculate the exact date 6 months from any start date. Get total days, business days, weekly breakdown, and monthly distribution instantly.
8-Hour Shift Calculator — Calculate shift end times, work hours, break deductions, overtime pay, and weekly earnings for 8-hour and custom-length work shifts.
60-Day Calculator — Calculate the exact date 60 days from any start date. Get business day counts, milestones, monthly breakdown, and weekday distribution instantly.
Add Minutes Calculator — Add or subtract minutes from any time. Convert minutes to hours, seconds, and decimal hours with AM/PM time results and duration comparisons.
90-Day Calculator — Calculate the exact date 90 days from any start date. Get quarterly milestones, business days, weekly breakdown, and monthly distribution.
Add Time Calculator — Add or subtract two time durations in hours, minutes, and seconds. Get results in multiple formats including decimal hours and total seconds.
Add or Subtract Days Calculator — Add or subtract any number of days from a date. Enter a start date and number of days to find the resulting date with full calendar accuracy.
Adding Hours Calculator — Add or subtract hours from any clock time. See result in AM/PM format with day shifts, repeating schedules, and unit conversions.
Adding Hours and Minutes Calculator — Add hours and minutes to any clock time. Get results in AM/PM format with decimal hours, progress timeline, and day shift indicators.
Age Difference Calculator — Calculate the exact age difference between two people in years, months, days, weeks, and hours from their birth dates.
Age Calculator — Calculate exact age in years, months, and days from a birth date. Get your precise age breakdown including total months, weeks, days, and hours.
Age in Hours Calculator — Calculate your exact age in hours from your date of birth. See milestones, progress through current year, and equivalent days, minutes, and seconds.
Age in Days Calculator — Calculate your exact age in days from your birthdate. Enter your date of birth and a reference date to see how many days you have been alive.
Age in Months Calculator — Calculate your exact age in months from your date of birth. See year breakdown, month progress, and equivalent weeks, days, and hours.
Age in Minutes Calculator — Calculate your exact age in minutes from your date of birth. See milestones, day progress, and equivalent hours, days, and seconds.
Age in Seconds Calculator — Calculate your exact age in seconds from your date and time of birth. See milestones, heartbeat estimates, and conversions to all time units.
Age in Weeks Calculator — Calculate your exact age in weeks from your date of birth. See life progress, weeks remaining, milestones, and a "Your Life in Weeks" visualization.
Age to Birthday Calculator — Calculate how many days until your next birthday. See upcoming birthdays with day of week, countdown progress, and milestone ages.
Age in Years Calculator — Calculate your exact age in years, months, and days from your date of birth. See decade milestones, birthday countdown, life progress, and fun facts.
Appliance Wattage Calculator — Calculate electricity cost for any appliance based on wattage, usage hours, and rate. See daily, monthly, and yearly costs with comparison tables.
Anniversary Calculator — Calculate how long you\'ve been together or employed. See years, months, days, traditional anniversary names, and upcoming milestone dates.
Birth Date from Death Date Calculator — Calculate a person\'s date of birth given their death date and age at death. Find birth day of week, zodiac sign, and total days lived.
Battery Charge Time Calculator — Estimate how long it takes to charge a battery from any percentage. Supports phones, laptops, EVs, and power tools with efficiency accounting.
Birth Year Calculator — Find your birth year from your current age. See your generation, decade, life milestones, and historical events from your birth decade.
Birthday Calculator — Enter your birthday to see exact age, days until next birthday, zodiac signs, day of week born, and upcoming birthday table with 8 future dates.
Business Days Between Dates Calculator — Count the number of business days (weekdays) between two dates. Excludes weekends automatically for accurate working day calculations.
Birthday Countdown Calculator — Count down the days, hours, and minutes until your next birthday. See fun countdown units, monthly progress, and the day of week your birthday falls on.
Century & Millennium Calculator — Determine which century and millennium any year belongs to. Enter a year to find its century number, millennium, and era classification.
Calendar Countdown Calculator — Count down to any calendar date — holidays, events, deadlines. See days, weeks, hours, workdays, and weekends remaining with visual progress bar.
Clay Shrinkage Calculator — Calculate clay shrinkage percentages for drying and firing stages. Plan wet dimensions for desired fired size with common clay type references.
Chronological Age Calculator — Calculate exact chronological age in years, months, days, hours, minutes, and seconds. See life stage, decimal age, heartbeats, and breaths since birth.
Clock Duration Calculator — Calculate the exact duration between two clock times in hours, minutes, decimal hours, and quarter-hour blocks. Supports breaks and overnight shifts.
Cost per Minute Calculator — Calculate the cost per minute, per second, and per hour from any total cost and duration. Compare rates across services and time periods instantly.
Countdown Calculator — Count down to any future event or date. See days, hours, minutes, business days, milestone dates, and multiple time unit conversions at a glance.
Count Hours Calculator — Count the total hours between two dates and times. Optionally exclude weekends, view weekday vs weekend split, and see monthly hour breakdowns.
Data Usage Calculator — Estimate internet data consumption by speed and usage hours. Check against data caps, compare activity rates, and project daily, weekly, and monthly usage.
Countdown to Retirement Calculator — Calculate the exact number of days, weeks, and months until your retirement date. Enter your retirement date and see a detailed countdown breakdown.
Date Countdown Calculator — Count down the days until any future date. Enter a target date and reference date to see exactly how many days, weeks, and hours remain.
Date Calculator — Add or subtract days, weeks, months, and years from any date. See the result date with day of week, quarter, week number, and quick reference table.
Date of Birth from Age Calculator — Estimate your date of birth from a known age in years, months, and days. Reverse-calculate an approximate birth date from any reference date.
Date to Date Calculator — Calculate the exact difference between two dates in days, weeks, months, years, business days, hours, and minutes with monthly distribution breakdown.
Day Counter Calculator — Count total days between two dates with weekday distribution, monthly breakdown, business vs weekend days, and inclusive/exclusive end-date toggle.
Day Countdown Calculator — Count the days until any event or holiday. See business days, weekend days, sleeps, monthly breakdown, and milestone markers from today to your target date.
Day of Year Calculator — Find the ordinal day number (1-366) for any date. Enter a date to see which day of the year it is and how many days remain in the year.
Day of Week Calculator — Find the day of the week for any date using Zeller's congruence. Enter any year, month, and day to instantly know if it falls on a Monday, Friday, etc.
Days Old Calculator — Find out exactly how many days old you are from your birth date. See weeks, hours, minutes, heartbeats, zodiac sign, generation, and day milestones.
Days Between Dates Calculator — Calculate the exact number of days between two dates. Enter any two dates using year, month, and day to find the total days between them instantly.
Days Until December Calculator — Count down the exact days, weeks, and hours until December 1st or any December date with holiday planning breakdowns.
Days Until Calculator — Calculate exactly how many days remain until any future date with weekday breakdown, business days, and milestone tracking.
Elapsed Time Calculator — Calculate the exact time elapsed between two dates and times with breakdowns in years, months, days, hours, minutes, and seconds.
Days Until June Calculator — Calculate exactly how many days remain until June 1st or any June date with summer planning breakdowns and event tracking.
Engine Hours to Miles Converter — Convert engine hours to approximate miles driven based on vehicle type and average speed for maintenance scheduling.
Fiscal Year & Quarter Calculator — Determine the fiscal year and quarter for any date based on your fiscal year start month. Supports any start month for custom fiscal calendars.
Expiration Date Calculator — Calculate expiration dates for food, medicine, documents, and more by adding shelf life to a start date.
Garbage Bag Size Calculator — Determine the right garbage bag size for any trash can with volume calculations, common size charts, and cost comparisons.
Fuel Mileage Calculator — Calculate your vehicle's fuel economy in MPG, cost per mile, and trip fuel costs with comparison charts and efficiency tips.
Generator Wattage Calculator — Calculate the total wattage needed for your generator by adding up appliances with starting and running watts.
Holiday Date Finder — Find the exact date of moveable US holidays for any year. Calculate Thanksgiving, Memorial Day, Labor Day, Easter, and more using calendar rules.
Hours Calculator — Convert between hours, minutes, seconds, days, and weeks with decimal and fraction formats for timesheets and scheduling.
Hour Countdown Calculator — Set an hour-based countdown timer to calculate exact end times, remaining minutes, and progress for any duration.
Hours Between Two Times Calculator — Calculate the exact hours and minutes between any two times with overnight support, break deduction, and payroll formatting.
Hours to Decimal Calculator — Convert hours and minutes (HH:MM) to decimal format for timesheets, payroll, and billing with batch conversion support.
Keystrokes Per Hour Calculator — Calculate your typing speed in keystrokes per hour (KPH) from WPM, CPM, or timed tests for data entry job requirements.
Julian Date Converter — Convert any Gregorian calendar date to a Julian Day Number and back. Enter a date to get the JDN, or enter a JDN to get the Gregorian date.
Korean Age Calculator — Calculate your Korean age from your birthdate and compare it with international age using the traditional Korean counting system.
Leap Year Checker — Check if any year is a leap year using the Gregorian calendar rules. Enter a year to find out instantly if it has 366 days or 365 days.
Microwave Wattage Calculator — Convert microwave cooking times between different wattage levels and calculate energy cost for optimal heating results.
Lunar Age Calculator — Calculate your age in lunar years and months based on the lunar calendar cycle used in Chinese and other Eastern traditions.
Minutes Between Two Times Calculator — Calculate the exact minutes between any two times with overnight support, visual breakdown, and common use case presets.
Minute Calculator — Convert minutes to hours, seconds, days, and other time units with a multi-entry adder for activity tracking and scheduling.
Months Between Dates Calculator — Calculate the number of full calendar months between two dates. Enter two dates and get the precise count of complete months between them.
Month Counter Calculator — Count the exact months between two dates with day-level precision, business month tracking, and milestone calculations.
Palindrome Date Calculator — Find palindrome dates that read the same forwards and backwards in multiple formats (MM/DD/YYYY, DD/MM/YYYY, YYYYMMDD).
Number of Days Calculator — Calculate the exact number of days between any two dates with business day, weekend, and holiday breakdowns.
Pregnancy Due Date Calculator — Estimate a pregnancy due date using Naegele's Rule. Enter the first day of the last menstrual period to calculate the estimated delivery date.
Pregnancy Countdown Calculator — Track your pregnancy week by week with a due date countdown, trimester timeline, baby development milestones, and key appointment dates.
Sidereal Time Calculator — Calculate local sidereal time (LST) and Greenwich sidereal time (GST) for astronomy, telescope alignment, and star observation planning.
Reverse Time Calculator — Subtract hours, minutes, and seconds from a time to work backwards and find start times from known end times.
Subtract Time Calculator — Subtract hours, minutes, and seconds from a time value to find the earlier time with date crossing and format conversion.
Slack Time Calculator — Calculate slack (float) time in project schedules using task durations, dependencies, earliest/latest start and finish times.
Time Calculator — Add, subtract, multiply, and convert time values with support for hours, minutes, seconds, and multiple output formats.
TikTok Time Alternatives Calculator — Calculate what you could accomplish in the time spent on TikTok or social media with productivity comparisons and goal tracking.
Time Between Dates Calculator — Calculate the exact time between any two dates in years, months, days, hours, minutes, and seconds with multiple breakdown formats.
Time Adder Calculator — Add multiple time durations together for timesheets, exercise logs, project tracking, and payroll calculations.
Time In Between Calculator — Find the exact midpoint, third-points, and quarter-points between any two times for scheduling and planning.
Time Difference Calculator — Calculate the exact difference between two clock times with overnight detection, break deduction, and multiple output formats.
Time Until Calculator — Calculate the exact time remaining until any future event with countdown in years, months, days, hours, minutes, and seconds.
Time to Hours Conversion Calculator — Convert time in hours, minutes, seconds to decimal hours, fractional hours, and payroll formats for billing and timesheets.
Vacation Countdown Calculator — Count down to your next vacation with days remaining, business days until you leave, packing timeline, and preparation milestones.
TV Series Duration Calculator — Calculate the total time to binge-watch any TV series based on episode count, length, and viewing schedule.
Wedding Countdown Calculator — Count down to your wedding day with detailed planning milestones, vendor deadlines, and a complete preparation timeline.
Week Calculator — Calculate week numbers, find dates by week, convert between ISO weeks and dates, and analyze weekly patterns.
Working Days Calculator — Calculate the number of business days between two dates, add or subtract working days, and account for custom holidays.
Week Number Calculator — Find the ISO 8601 week number for any date. Enter a year, month, and day to instantly see which week of the year it falls in.
Years Between Dates Calculator — Calculate the exact number of full years between two dates. Get precise results with remaining months and days for any date pair.