Date Duration Calculator
Count elapsed days, weeks, and completed months between two dates. Compare calendar dates without time-of-day or daylight-saving effects. The result is elapsed days, not a legal or business-day count.
Use the tool
Enter your values, then run it. The result is generated in your browser.
Result
Calculated
How to use Date Duration Calculator
- Choose start and end dates.
- A negative count means the end date precedes the start date.
- Confirm inclusive/exclusive and holiday counting rules for deadlines.
Formula and assumptions
Elapsed days = difference between the two dates at midnight UTC. Month count is a completed-calendar-month estimate.
Legal, billing, and contract deadlines can use special counting rules. Do not rely on this for a legal deadline.
Frequently asked questions
Does it count both dates?
No, it reports elapsed difference; same date equals zero.
Does it count business days?
No, public holidays vary by location.
Can end date come first?
Yes, the result is signed.
About this tool
Compare calendar dates without time-of-day or daylight-saving effects. The result is elapsed days, not a legal or business-day count.
No account is required. The tool runs in this browser and this starter build has no form-submission backend. See the method and assumptions before relying on estimates.