Date Difference Calculator
Find the number of days, weeks, months, and years between dates.
● Processed locally in your browser unless the page says otherwise.
Inclusive or exclusive?
How date difference is calculated
A date difference calculator finds the number of days, weeks, months, or years between two dates. Common uses include project schedules, leases, countdowns, warranties, work planning, and travel length.
Be clear about whether the start date or end date should be included. Different situations count dates differently. Hotel stays, event days, and deadlines may not use the same rule.
Formula or logic
- Date difference = End date - Start date
- Including the start or end date depends on the use case
Example
If an event runs from August 1 to August 10, the simple date difference is 9 days. If both the first and last day count as event days, it may be treated as 10 days.
Common questions
Why is the result different from what I expected?
It is often because of whether the start date or end date is included. Check the counting rule for your situation.
Can I divide days by 30 to get months?
That is only a rough estimate. Calendar months have different lengths, so exact month differences should use calendar rules.
Can this be used for contracts?
It can help with a rough check, but formal contract periods should follow the contract wording and applicable rules.