Date Difference Calculator – How Long Between Two Dates
Pick a start and end date to see the difference.
About Date Difference Calculator
Pick any two dates and see the exact gap between them: years, months and days following the real calendar, plus running totals in days, weeks and months.
Counting days between dates by hand goes wrong quickly, because months are different lengths and leap years add a day. This calculator walks the actual calendar rather than treating every month as 30 days, so the years-months-days figure matches how people actually count elapsed time.
It gives two views of the same gap. The calendar-accurate breakdown is what you want for things like notice periods and anniversaries. The straight totals — total days, total weeks — are what you want for deadlines, project planning, and anything counted in whole days.
What you can use it for
- Count the days remaining until a deadline, a trip or an exam.
- Work out how long you have been in a job, a home or a relationship.
- Check a notice period or a contract term between two specific dates.
- Find how many weeks are left in a project schedule.
- Count back to find how long ago something happened.
How it works, step by step
- 1
Pick the first date
Choose the start date from the date field.
- 2
Pick the second date
Choose the end date. The order does not matter.
- 3
Read the exact difference
Years, months and days are shown together, following the real calendar.
- 4
Check the totals
Total days, weeks and months are listed alongside for planning purposes.
Frequently asked questions
How do I count the days between two dates?
Enter both dates and the total day count appears immediately. Counting by hand is error-prone because of varying month lengths and leap years.
Are leap years handled?
Yes. Leap days are included in both the calendar breakdown and the total day count.
Does the count include both the start and end dates?
The total is the number of days between the two dates. If you need to count both endpoints as whole days — as some notice periods and bookings do — add one to the total.
Why do the months and days look uneven?
Because real months are not equal. The breakdown counts whole calendar months first and then the leftover days, so the day figure depends on which months the period spans.
Can I use future dates?
Yes. Either date can be in the past or the future.