Date arithmetic, age, countdown, and calendar tools. Browse our free date tools below — all calculators are instant, accurate, and require no sign-up.
100-Day Calculator — Calculate the exact date 100 days from any start date. Find milestones, weekday, weekly breakdown, and monthly distribution instantly.
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.
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.
30-Day Calculator — Calculate the exact date 30 days from any start date. Find weekday, business days, milestones, and time breakdowns for monthly planning.
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.
60-Day Calculator — Calculate the exact date 60 days from any start date. Get business day counts, milestones, monthly breakdown, and weekday 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.
90-Day Calculator — Calculate the exact date 90 days from any start date. Get quarterly milestones, business days, weekly breakdown, and monthly distribution.
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.
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.
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.
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 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 Difference Calculator — Calculate the exact age difference between two people in years, months, days, weeks, and hours from their birth dates.
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 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 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 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 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 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.
Age to Birthday Calculator — Calculate how many days until your next birthday. See upcoming birthdays with day of week, countdown progress, and milestone ages.
Anniversary Calculator — Calculate how long you\'ve been together or employed. See years, months, days, traditional anniversary names, and upcoming milestone dates.
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.
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 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.
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 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.
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.
Calendar Countdown Calculator — Count down to any calendar date — holidays, events, deadlines. See days, weeks, hours, workdays, and weekends remaining with visual progress bar.
Business Days Between Dates Calculator — Count the number of business days (weekdays) between two dates. Excludes weekends automatically for accurate working day calculations.
Century & Millennium Calculator — Determine which century and millennium any year belongs to. Enter a year to find its century number, millennium, and era classification.
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.
Clay Shrinkage Calculator — Calculate clay shrinkage percentages for drying and firing stages. Plan wet dimensions for desired fired size with common clay type references.
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.
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.
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.
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.
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.
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 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 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 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 Counter Calculator — Count total days between two dates with weekday distribution, monthly breakdown, business vs weekend days, and inclusive/exclusive end-date toggle.
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 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.
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.
Days Until Calculator — Calculate exactly how many days remain until any future date with weekday breakdown, business days, and milestone tracking.
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 Until December Calculator — Count down the exact days, weeks, and hours until December 1st or any December date with holiday planning breakdowns.
Days Until June Calculator — Calculate exactly how many days remain until June 1st or any June date with summer planning breakdowns and event tracking.
Elapsed Time Calculator — Calculate the exact time elapsed between two dates and times with breakdowns in years, months, days, hours, minutes, and seconds.
Engine Hours to Miles Converter — Convert engine hours to approximate miles driven based on vehicle type and average speed for maintenance scheduling.
Expiration Date Calculator — Calculate expiration dates for food, medicine, documents, and more by adding shelf life to a start date.
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.
Fuel Mileage Calculator — Calculate your vehicle's fuel economy in MPG, cost per mile, and trip fuel costs with comparison charts and efficiency tips.
Garbage Bag Size Calculator — Determine the right garbage bag size for any trash can with volume calculations, common size charts, and cost comparisons.
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.
Hour Countdown Calculator — Set an hour-based countdown timer to calculate exact end times, remaining minutes, and progress for any duration.
Hours Calculator — Convert between hours, minutes, seconds, days, and weeks with decimal and fraction formats for timesheets and scheduling.
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.
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.
Keystrokes Per Hour Calculator — Calculate your typing speed in keystrokes per hour (KPH) from WPM, CPM, or timed tests for data entry job requirements.
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.
Lunar Age Calculator — Calculate your age in lunar years and months based on the lunar calendar cycle used in Chinese and other Eastern traditions.
Microwave Wattage Calculator — Convert microwave cooking times between different wattage levels and calculate energy cost for optimal heating results.
Minute Calculator — Convert minutes to hours, seconds, days, and other time units with a multi-entry adder for activity tracking and scheduling.
Minutes Between Two Times Calculator — Calculate the exact minutes between any two times with overnight support, visual breakdown, and common use case presets.
Month Counter Calculator — Count the exact months between two dates with day-level precision, business month tracking, and milestone calculations.
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.
Number of Days Calculator — Calculate the exact number of days between any two dates with business day, weekend, and holiday breakdowns.
Palindrome Date Calculator — Find palindrome dates that read the same forwards and backwards in multiple formats (MM/DD/YYYY, DD/MM/YYYY, YYYYMMDD).
Pregnancy Countdown Calculator — Track your pregnancy week by week with a due date countdown, trimester timeline, baby development milestones, and key appointment dates.
Reverse Time Calculator — Subtract hours, minutes, and seconds from a time to work backwards and find start times from known end times.
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.
Sidereal Time Calculator — Calculate local sidereal time (LST) and Greenwich sidereal time (GST) for astronomy, telescope alignment, and star observation planning.
Slack Time Calculator — Calculate slack (float) time in project schedules using task durations, dependencies, earliest/latest start and finish times.
Subtract Time Calculator — Subtract hours, minutes, and seconds from a time value to find the earlier time with date crossing and format conversion.
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 Calculator — Add, subtract, multiply, and convert time values with support for hours, minutes, seconds, and multiple output formats.
Time Adder Calculator — Add multiple time durations together for timesheets, exercise logs, project tracking, and payroll calculations.
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 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 to Hours Conversion Calculator — Convert time in hours, minutes, seconds to decimal hours, fractional hours, and payroll formats for billing and timesheets.
Time Until Calculator — Calculate the exact time remaining until any future event with countdown in years, months, days, hours, minutes, and seconds.
TV Series Duration Calculator — Calculate the total time to binge-watch any TV series based on episode count, length, and viewing schedule.
Vacation Countdown Calculator — Count down to your next vacation with days remaining, business days until you leave, packing timeline, and preparation milestones.
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.
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.
Working Days Calculator — Calculate the number of business days between two dates, add or subtract working days, and account for custom holidays.
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.