Date Difference
Find the exact number of days, months and years between two dates
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
All dates and times follow your device's time zone
About this tool
Counting days between dates by hand goes wrong in predictable ways: months have different lengths, February changes size every four years, and it is genuinely easy to be off by one depending on whether you count both end dates or neither. The ambiguity matters in practice. A contract running "30 days from 1 March" ends on a different day depending on whether you include the first day, and notice periods, visa durations and payment terms all hinge on exactly that convention. This tool gives you both the total number of days and a broken-down years, months and days figure, because those answer different questions - "how many days until the deadline" and "how long have I lived here" are not the same request. Leap years are handled correctly, which is where manual counting most often fails. Everything is calculated in your browser.
How to use this tool
- Enter the first dateThe earlier date, or the start of the period you are measuring.
- Enter the second datePast or future - the order does not matter, the span is calculated either way.
- Read both formatsTotal days for deadlines and durations; years, months and days for age and tenure.
- Check the counting conventionIf a contract or form specifies inclusive counting, add one day to the total.
How to count days between two dates
The usual count excludes the start date and includes the end date: from 1 March to 31 March is 30 days. If both dates should count - a 7-night hotel stay is 8 calendar days, for example - add one.
Months have different lengths, so "one month" from 31 January lands on the last day of February. For deadlines in contracts, check whether the agreement counts calendar days or business days.
Key features
- Handles leap years and varying month lengths correctly, which manual counting routinely gets wrong.
- Gives both total days and a years/months/days breakdown, since each answers a different question.
- Works in either direction - past or future dates, in any order.
- Runs in your browser with nothing recorded.
- No account and no limit.
Common uses
- Calculating exact age in years, months and days for a form.
- Counting days until a deadline, exam, wedding or trip.
- Working out project duration or employment tenure.
- Checking a notice period or contract term.
- Confirming visa or permit duration in days.
Tips for better results
- Decide whether your count should be inclusive before you rely on it. Legal and contractual periods frequently count the first day.
- For age, the years/months/days breakdown is what forms usually want, not the total day count.
- Watch date format when typing - 03/04 is March 4th in the US and 3rd April almost everywhere else.
- For working days rather than calendar days, the Business Days Calculator excludes weekends.
- Anniversary dates in leap years are worth double-checking, particularly anything dated 29 February.
Mistakes to avoid
- Being off by one because the counting convention was never established - inclusive versus exclusive changes the answer.
- Ignoring leap years when counting manually, which quietly adds a day per four years.
- Confusing calendar days with working days on a deadline that specified business days.
- Mixing up day-first and month-first date formats, which produces a plausible but wrong answer.
- Assuming "one month" always means 30 days. It means the same date next month, which is 28 to 31 days.
Frequently asked questions
Yes - rather than just showing total days, it typically gives a combined breakdown (like "2 years, 3 months, 15 days") for a more intuitive sense of the time span.
Yes - the calculation properly accounts for leap years when determining the exact difference between dates.
Yes - enter any two dates, whether both in the past, both in the future, or one of each, and the tool calculates the span between them.
That depends on the context, and it is worth checking. Legal notice periods and contract terms often count inclusively, meaning you add one day to the plain difference. Deadlines and countdowns usually do not. The convention should be stated in whatever document set the period.
Because a month means the same date in the following month, which is 28, 29, 30 or 31 days depending on where you start. This is why total days and the years/months/days breakdown give different-looking answers for the same period.
No. The calculation runs in your browser and nothing is transmitted or saved.
Subtract weekends from the total - roughly five of every seven days - and then public holidays. For an exact count of business time, use the business hours calculator, which skips weekends for you.
Enter your birth date as the start and today as the end. The result shows years, months and days, and the total in days - useful for milestones such as your 10,000th day.
90 days is 12 weeks and 6 days. Visa rules such as the Schengen 90-in-180-day limit count calendar days, including the days you arrive and leave, so check how your rule counts before relying on a figure.