About the Date Difference Calculator
How long ago did something happen? How long did a project, a job or a relationship last? How much time is left on a contract? The date difference calculator measures the time between any two dates and expresses it in every useful way: as years, months and days, and as totals in months, weeks, days, hours and minutes, along with the number of weekdays in between.
Unlike a simple day counter, it gives the calendar breakdown people use in everyday speech — "2 years, 6 months and 14 days" — while also giving exact totals for calculations. You can enter the dates in either order; the calculator always measures from the earlier to the later date.
How to Use the Date Difference Calculator
Enter the start date and the end date.
The difference appears immediately, with all the totals.
How the Difference Is Calculated
1. Count the whole months from the start date that fit before the end date
2. Split them into years (÷ 12) and months (remainder)
3. Count the days left over
totals: days = end − start
weeks = days ÷ 7
hours = days × 24, minutes = days × 1,440If the start date is the 29th, 30th or 31st, monthly anniversaries in shorter months fall on the last day of the month.
Step-by-Step Example
From 15 March 2024 to 29 September 2026.
Whole months: 15 March 2024 → 15 September 2026 = 30 months = 2 years 6 months
Days left: 15 September → 29 September = 14 days
Result: 2 years, 6 months, 14 days
Totals: 928 days = 132 weeks 4 days = 22,272 hours = 1,336,320 minutes
662 weekdays (Monday to Friday)The range contains no 29 February: it starts on 15 March 2024, after that year's leap day, and ends before the next one in 2028, so every year in it has 365 days.
Calendar Breakdown Versus Totals
The two kinds of answer serve different purposes. The calendar breakdown is how people naturally describe durations — ages, lengths of service, time since an event — and it respects the fact that months differ in length. The totals are exact and unambiguous, and are what you need for calculations such as daily interest, pay per day, or the number of doses in a course of medicine. A month in the breakdown may be 28, 29, 30 or 31 days, but a day in the totals is always a day.
Inclusive or Exclusive?
This calculator counts from the start date up to the end date, the way elapsed time is normally measured: from Monday to Tuesday is one day. If you need to count both the first and last days — for example, a conference running from Monday to Friday is five days, not four — add one to the total. The days between dates calculator has an option to include the end date automatically.
Weekdays in the Range
The weekday count includes each Monday to Friday from the start date up to, but not including, the end date. It is useful for rough estimates of working time, but it does not remove public holidays, which vary by country and region. For precise working-day counts, use a business days calculator and subtract the holidays that apply to you.
Hours and Minutes
The hours and minutes figures assume whole days from midnight to midnight. They do not account for the clocks changing for daylight saving time, when one day in spring has 23 hours and one in autumn has 25 in many countries. For elapsed time measured to the hour between two specific times, use a time duration calculator instead.
Why Two Tools Can Disagree
Different calculators sometimes give different year-month-day answers for the same dates. The totals in days never differ, but the breakdown depends on conventions: some tools count the days first and then the months, some treat every month as 30 days, and some borrow days from the start month rather than the end month. This calculator uses the most common convention, counting whole calendar months from the start date and then the days left over, which matches how ages and service lengths are normally stated. If a difference of a day matters, compare the total days, which are unambiguous.
Everyday Uses
The date difference is useful for ages and anniversaries (how long a couple has been married), employment (length of service for a reference, notice period or redundancy pay), history (how long ago an event occurred), projects (how long a phase actually took), legal and financial periods (how long a loan or lease has run) and personal milestones (how long since you quit smoking or started a habit).
Understanding Your Result
The headline is the difference in years, months and days.
The total days, weeks, months and hours and minutes lines give the same span in other units.
The weekdays line counts Monday to Friday days in the range.
The dates line confirms the dates used, and notes if they were swapped.
When Should You Use This Calculator?
Use it to find how long ago something happened.
Use it to measure the length of a job, tenancy or relationship.
Use it to express a duration in the unit a form asks for.
Use it to check the length of a contract or loan period.
Common Mistakes
Dividing days by 30 to get months. Months vary in length; use the calendar breakdown.
Forgetting to include the end date when needed. Add one for inclusive counts.
Assuming weekdays equal working days. Public holidays are not removed.
Mixing up day and month order. Enter dates as year-month-day.
Expecting daylight saving to be included. The hour totals use 24-hour days, so they may be an hour out across a clock change.