Time & Date
Date Difference
Calendar days between dates.
Educational estimates only. Not medical, legal, tax, or financial advice.
Guide: Date Difference
What it does
Subtracts dates in the Gregorian calendar.
How to use it
Pick start and end dates, then calculate.
Formula
Difference in milliseconds ÷ ms per day, adjusted for DST if using local midnight.
Example
Jan 1 to Jan 10 → 9 days between (exclusive) or 10 inclusive depending on mode.
FAQs
Inclusive vs exclusive?
Check whether the tool counts both endpoints; definitions vary.
Order of dates?
Swap if you get negative duration; some tools use absolute difference.
Business days?
This counts calendar days; business-day math excludes weekends/holidays separately.