How many days between two dates
Pick two dates. The result is whole calendar days, and it says whether the last day is counted, because that is the one thing everyone gets a different answer on.
From Saturday, September 26, 2026 to Monday, October 26, 2026
30 days
4 weeks and 2 days. Counting both the first and last day, it is 31 days.
Inclusive or exclusive?
From Monday to Wednesday is two days if you count the gaps between them, and three if you count Monday, Tuesday and Wednesday as days you were there. Neither is wrong — they answer different questions. Hotel nights, notice periods and "days until" all use the first kind. Trip length, days worked and rental days usually use the second. The calculator shows both so you can pick the one your situation needs.
Weeks and months
Weeks are simple: divide by seven. Months are not, because months have 28 to 31 days, so "how many months between two dates" depends on whether you count whole months or a fraction. This page gives you days and weeks, which are exact. For a countdown to a specific date in your time zone, use the countdown maker.
Questions people ask
Does this count today?
The first date is the starting point and is not counted as a day passed. If you want it counted, use the "counting both the first and last day" figure in the result.
Does it count weekends?
Yes — this counts every calendar day. A business-days calculator that skips weekends and public holidays is a different tool.
Is there a date calculator app?
The Countdown app for iPhone does the days-until part with a live widget on your lock screen. For arithmetic between two arbitrary dates, this page is the tool, and it works on your phone's browser without installing anything.
Counting down to a specific date rather than doing arithmetic? The Countdown app for iPhone puts it on your lock screen.