How the difference between dates is counted
The gap between two dates can be expressed two ways, and this calculator gives both. The calendar breakdown — years, months and days — counts whole calendar units the way you would on a wall calendar, borrowing days from the previous month so it stays accurate across months of different lengths. The total-days figure simply counts every day between the two dates, including leap days. If you enter the dates in the wrong order, the calculator swaps them automatically and shows the positive difference, so you always get a sensible answer.
Days, weeks or months — which to use
Different tasks call for different units. Project deadlines and notice periods are usually counted in days; pregnancy and infant milestones in weeks; and contracts, leases or subscriptions in months and years. The total-days count is the most precise and is ideal for countdowns, interest accrual or working out how long until an event. The months figure is approximate because months vary in length, so for anything legal or financial, prefer the exact day count this calculator provides.
Planning deadlines and countdowns
Knowing the exact number of days until a date removes guesswork from planning. Use it to count down to a launch, a wedding, an exam or a trip; to check whether a deadline gives you enough working time; or to verify a notice period or warranty window. Because the calculator counts real calendar days rather than estimating, you can rely on the figure for scheduling and contracts where being a day out actually matters.
Inclusive vs exclusive counting
This calculator measures the span between two dates, counting the days from the start date up to the end date. Some contexts count both endpoints — for example, 'how many days is this event running' often includes the first and last day, which is the difference plus one. If your situation counts both ends, add a day to the total. For most countdowns and durations, the straight difference shown here is exactly what you want.
Frequently asked questions
How many days are between two dates?
Enter the start and end date and the calculator counts every calendar day between them, including leap days, and also shows the gap in weeks, months and years.
Does the order of the dates matter?
No. If you enter the later date first, the calculator swaps them automatically and shows the positive difference.
Why is the months figure approximate?
Calendar months vary in length, so a count in months can never be as exact as a count in days. For precise needs, use the total-days figure.
Does it count both the start and end day?
It measures the span between the two dates. If you need to include both endpoints — common for event durations — add one day to the total.