Age Calculator
Find exact age in years, months, days, total days lived, and days until the next birthday.
Days Between Dates
Count calendar days, weeks, months, and years between two dates with optional end-date inclusion.
Date Calculator
Add or subtract years, months, weeks, and days from a date while handling month-end dates correctly.
Business Days Calculator
Count weekdays between dates and exclude weekends or custom holiday dates from workday totals.
Time Duration Calculator
Calculate elapsed time between two dates and times in days, hours, minutes, and seconds.
Time Card Calculator
Total weekly work hours, lunch breaks, regular hours, and overtime from daily clock-in and clock-out times.
Common Date and Time Calculations
Date math shows up in ordinary decisions more often than it seems: school cutoff dates, payroll periods, travel plans, lease terms, warranty windows, delivery estimates, project schedules, birthdays, and deadlines. The right calculator depends on whether the question is about a person's age, the gap between two dates, a future or past calendar date, workdays, elapsed clock time, or weekly work hours.
Use the age calculator when a date of birth needs to be converted into exact years, months, and days. That kind of result is better for eligibility dates, records, milestones, and birthday planning than a rough decimal age. Use the days between dates calculator when the important number is the total span between two calendar dates.
For deadline planning, the date calculator adds or subtracts years, months, weeks, and days from a start date. It is useful for finding a date 30 days from now, backing up 90 days from a due date, or calculating a reminder after a billing period. If weekends or holidays should not count, the business days calculator gives a workday total instead of a calendar-day total.
Time calculations are different from date-only calculations because hours and minutes can change the answer. Use the time duration calculator for elapsed time between two timestamps, such as an event start and end time. Use the time card calculator when the inputs are work shifts, breaks, weekly totals, hourly rates, and overtime estimates.
Choosing the Right Tool
If the input is a birth date, start with age. If the input is two calendar dates, use days between dates. If the goal is to find a future or past date, use date add/subtract. If the problem mentions workdays, business days, weekends, or holidays, use the business days tool. If the input includes clock times, use time duration or time card depending on whether the times are general timestamps or work shifts.
Calendar calculators and workday calculators answer different questions. A 10-day hotel stay, countdown, or warranty period normally counts every calendar day. A shipping estimate, service-level agreement, hiring timeline, or bank-processing window may count only weekdays and may need specific holidays removed. Choosing the wrong counting method can shift the answer by several days.
Month and year calculations also need care because months are not equal lengths. Adding one month to January 31 is not the same as adding 30 days, and leap years can affect birthdays, long spans, and annual dates. The individual calculators explain these assumptions on the page so the result is easier to read and apply.