Date Difference Calculator
Find the exact span between two dates — years, months and days, plus totals in days, weeks and hours, with optional business-days-only counting.
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Difference
{{ result.years }}y {{ result.months }}m {{ result.days }}d
- Total days
- {{ result.totalDays }}
- Total weeks
- {{ result.totalWeeks }}
- Total hours
- {{ result.totalHours }}
- Total days
- {{ result.totalDays }}
- Total weeks
- {{ result.totalWeeks }}
- Total hours
- {{ result.totalHours }}
- Business days
- {{ result.businessDays }}
Enter a start and end date above to see the difference.
Every calculation runs in your browser. Nothing you enter is uploaded to a server.
How the difference is calculated
Years, months and days are calendar-exact, the same borrowing method used by the Age Calculator. Total days, weeks and hours are derived from that same exact day count, not an approximation.
Include end date counts the end day itself as part of the span — useful for "how many days of a booking is this" where both check-in and check-out days count. Off by default, which measures the gap between the two dates instead.
Business days only counts Monday through Friday in the span and ignores weekends. It does not know about public holidays in any region — subtract those yourself if they apply.
What this is useful for
Contract and notice periods, project timelines, warranty windows, and "how many days since" or "how many days until" questions all come down to the same calculation: the exact span between two calendar dates. Turning on business-days-only mode matches how deadlines are usually counted in billing, HR and legal contexts, where weekends don't count toward the clock.
Frequently asked questions
What does "include end date" change?
It counts the end day itself as part of the span, adding one day to every total. Useful for something like a hotel stay where both the check-in and check-out day should count; off by default, which measures the gap between the two dates instead.
How are business days counted?
Monday through Friday within the span, with no adjustment for public holidays in any region — subtract those yourself if they apply to your calculation.
Why do total days and the years/months/days breakdown look inconsistent for oddly-spaced dates?
They aren't inconsistent — total days is an exact day count, while years/months/days is a calendar breakdown that borrows days from real calendar months, so a 31-day month and a 30-day month contribute differently to the same total.
Can the end date be before the start date?
No — swap them. The tool always measures forward from start to end and shows a clear message if the end date comes first.
Is this the same calculation as the Age Calculator?
The same underlying calendar math, yes — the Age Calculator is this same date-difference logic specialized for "birth date to today", with a next-birthday calculation added.