Choose the calculation mode
Select 'Date difference' to measure the span between two dates, or 'Date offset' to find the date that is N days before or after a starting point.
Free, privacy-first
Date Difference Calculator
Measure the gap between two dates, check the signed difference, and compare calendar days with workday context.
Date settings
Results
Results update as you use the interface above.
How to use this calculator
Choose a calculation mode, set the dates or offset, and optionally add holidays to refine the workday count.
Set the counting focus
Switch between workdays (weekdays only) and calendar days to match the planning convention your project, contract, or team uses.
Add holiday exclusions
Paste any public holiday or non-working dates in YYYY-MM-DD format, one per line. These are excluded from the workday count so the result reflects your actual schedule.
Read the result
The output shows calendar days, workday count, and (in offset mode) the resulting target date. Use negative offsets to back-calculate from a deadline.
Frequently Asked Questions
What is the difference between calendar days and workdays?
Calendar days count every day in the span. Workdays count only weekdays and skip any holiday dates you add manually.
Can I add holidays?
Yes. Paste holiday dates in YYYY-MM-DD format to exclude them from workday math.
Does the offset mode work backwards?
Yes. Negative offsets move backwards from the start date in either calendar-day or workday mode.
Is this a replacement for payroll or legal calendars?
No. It is a planning tool. Always validate high-stakes deadlines and jurisdiction-specific calendars separately.
Does the calculator fetch public holiday data automatically?
No. Holiday handling only uses the dates you enter yourself.