Date Difference Calculator

How many days until your vacation? How long has a project been running? The date difference calculator answers these questions instantly, giving the exact day count plus approximate weeks, months, and years.

• Project planning: Know exactly how many days remain until a deadline.
• Contract durations: Calculate how long a contract has run or will run.
• Travel planning: Find out how many days between booking and departure.
• Loan and lease terms: Verify the exact duration of a financial agreement.

1. 1Enter the start date and end date in YYYY-MM-DD format.
2. 2The calculator converts both dates to timestamps and subtracts.
3. 3Total days is exact. Weeks, months, and years use average period lengths.
4. 4A calendar breakdown (years, months, days) is also shown.

• Confusing calendar days with working days: This calculator counts every day between two dates, including weekends and holidays. If a contract or deadline specifies "business days," use the working days calculator instead.
• Off-by-one errors around the start date: Whether to include the start date depends on the context. A contract starting January 1 and ending January 31 is either 30 or 31 days depending on whether the first day counts. Check the convention in your agreement.
• Entering dates in the wrong order: The calculator uses start and end date. If start is after end, most calculators will return an error or a negative number. Always enter the earlier date as start.
• Using approximate month and year conversions: The months and years shown are approximate. Months vary from 28 to 31 days. For legal or contractual precision, use only the exact day count, not the month or year approximations.

• Use it to verify invoice due dates: A NET-30 invoice issued on March 15 is due April 14 (not April 15, as 30 days from March 15 brings you to April 14). Verify payment terms for early payment discounts too.
• Calculate subscription length: Enter your subscription start date and today's date to see exactly how long you have been a customer. Useful for prorating refunds or calculating value-per-day from a subscription cost.
• Find mid-points in a range: Add the day count to the start date to find the halfway point in a project timeline. Or use it in reverse: if a project needs 90 days and must end by a fixed date, count back 90 days to find the latest possible start.
• Pair with the working days calculator for deadlines: Run date difference to get the total calendar days, then working days to get the business days. The gap between the two tells you how many weekends fall within the range.