Date difference & day counter
Date difference & day counter: use start date, end date. Review the formula, worked example and calculation steps.
Inputs
Use the units shown—
Enter your values and select Calculate.
Formula & explanation
Calendar days = (end UTC midnight − start UTC midnight)/86,400,000
Variables & units
- Start date
- Gregorian date
- End date
- Gregorian date
Worked example
2026-01-01 to 2026-02-01 is 31 days.
Assumptions
The start date is excluded. Negative means the end precedes the start; daylight saving does not affect date-only subtraction.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
Use the default input values to find the answer. The reset icon restores those values.
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