Date & Time Calculators
Count days, add business days and measure age in the units that matter.
Dates are deceptively tricky: leap years, month lengths and weekends all change the answer. These calculators handle calendar arithmetic in your browser, from the days between two dates to the date after a set number of working days.
All Calculators43
Days Between Dates Calculator
Count calendar days, weeks and weekdays between two dates.
Business Days Calculator
Count weekdays between two dates, excluding weekends.
Add Days to Date Calculator
Find the date a chosen number of days before or after a date.
Age in Days Calculator
Convert a birth date into exact days, weeks and years.
Flight arrival time
Convert a departure time and flight duration into the local arrival time at the destination.
Meeting time across zones
Translate one meeting hour into three time zones and check who is inside working hours.
Time zone offset difference
Compare two UTC offsets and see the local clock time in each zone.
Add months to date
Shift a date forward or backward by a number of calendar months.
Age at future date
Find an exact age on a future or past reference date, down to years, months and days.
Age in months
Convert an exact age into completed calendar months and leftover days.
Age in weeks
Express an age as total weeks, with whole weeks, extra days and total days.
Baby age in weeks
Track the age of a baby in completed weeks and days from the birth date.
Break deduction
Subtract unpaid breaks from hours on shift to get paid time.
Countdown to event
Count the days, hours and minutes from a start date until an event.
Date format converter
Rewrite one calendar date in several common formats at once.
Days until birthday
Find how many days remain until the next birthday.
Duration between timestamps
Measure the exact elapsed time between two date-and-time points.
Next birthday
Get the date, weekday and wait for the next birthday.
Overnight shift duration
Calculate hours worked when a shift starts before midnight and ends after it.
Overtime hours
Separate regular and overtime hours above a weekly threshold and estimate overtime pay.
Project deadline
Add a project duration to a start date to find the deadline.
Subtract days from date
Find the date a chosen number of days before a starting date.
Timesheet total
Add Monday to Friday hours into a weekly timesheet total.
Unix timestamp converter
Convert a Unix timestamp to a readable date, or check the epoch value of a date.
Weekday for a date
See which day of the week any calendar date falls on.
Work hours between times
Deduct an unpaid break from a same-day work window to get paid hours.
Age Calculator - Find Your Exact Age from Date of Birth
Free age calculator to find your exact age in years, months, and days from any date of birth. Includes next birthday countdown.
Days Between Dates Calculator — Count Days, Weeks & Months Between Two Dates
How many days between two dates? Enter a start and end date to instantly count the exact days, weeks, months, and years between them. Includes business days, leap year handling, and add/subtract days from any date.
ISO week date
Turn a calendar date into its ISO year, ISO week number and weekday.
School start age
Work out a child’s age on a school entry cut-off and whether the minimum age is met.
Add business days
Find the working day that falls a chosen number of business days after a date.
Subtract business days
Find the date a chosen number of business days before a starting date.
Add years to date
Shift a date forward or backward by a whole number of years.
Age in hours
Convert a birth date and time into the total number of hours lived.
Anniversary countdown
Count the days until the next anniversary of an important date.
Date difference inclusive
Count every day in a date range, including both the start and the end date.
Days left in year
See how many days remain in the calendar year from a chosen date.
Holiday countdown
Count the days until the next New Year, Thanksgiving, Christmas or another common holiday.
Leap year checker
Test whether a year is a leap year under the Gregorian or Julian rule.
Retirement countdown
Estimate the working days left before a retirement date.
Tax deadline countdown
Count the days to a filing deadline and work out how much to set aside each week.
Wedding countdown
Count the days and weeks left before a wedding date.
Week number
Find the calendar week that contains a date, using ISO or US numbering.
Frequently asked questions
How are days between dates counted?
The main result is the difference between the two dates. The inclusive count adds one day when both the start and end date should be included.
Do business-day calculators include public holidays?
They exclude weekends but not public holidays. Subtract local holidays separately for contract or payroll deadlines.