Date duration calculator
Find the exact time between two dates, in years, months, days and total days.
Fill in the fields and press Calculate to see your result here.
How this calculation works
The calculator finds the calendar-accurate difference between the two dates (years, months and days), and also shows the total number of days and weeks, which is useful for contracts, deadlines and travel planning.
Worked example
From 1 January 2026 to 1 January 2027 is exactly 365 days (52.1 weeks) — 2026 isn't a leap year, so there's no extra day to account for.
Tips
Order doesn't matter
Enter the dates in either order — the calculator automatically works out the difference regardless of which one comes first.
Inclusive or exclusive?
The result is the gap between two dates. If you want to count both the first and last day, such as days of a course, add one.
Months are uneven
Months range from 28 to 31 days, so the years/months/days breakdown won't always equal the total days divided by 30.
Plan deadlines
Use it to see how many weeks remain before a deadline, an event or the end of a contract.
Frequently asked questions
Does it count the start or end day?
The day count reflects the elapsed time between midnight on the two dates; if you need an inclusive count (both end dates counted), add one day to the total.
Can I use this for countdowns?
Yes — put today's date as the start date and a future date as the end date to see how long is left.