Date Difference Calculator
Find the number of days between two dates — for a countdown to a future date or the gap since a past one.
How it's calculated
The total day count is a straightforward difference between the two calendar dates. The years/months/days breakdown borrows from the next larger unit when a subtraction goes negative — the same way you'd work it out on paper — so it stays accurate across different month lengths and leap years.
Common uses
- Counting down the days to an event, deadline, or trip
- Working out how long ago something happened
- Checking the length of a stay, lease, or project timeline
Frequently asked questions
Does it matter which date I enter first?
No — the calculator works out the gap either way round, so you can enter today's date and a future date, or two past dates, in any order.
Does this count the start or end day?
The total day count is the difference between the two calendar dates (an exclusive count of full days elapsed), which matches how 'days until' countdowns are typically expressed.