Dates & Time
Date Difference Calculator
Counting days between dates by hand goes wrong at month ends, and contracts rarely say whether the last day counts. Enter two dates to get the exact gap in several units, plus a weekday-only count for deadlines and billing.
Estimates only. Verify important figures against your own records before acting on them. See our disclaimer.
What this calculator includes
What you enter
- Start date
- End date
- Count the end date itself
- Holidays to exclude (optional)
What you get back
- Days between
- Calendar difference
- Business days
- Weeks
- Weekend days
- Months
- Hours
How this calculation works
How this calculation works
The plain day count is a subtraction. The calendar difference works in years, months, and days so it survives months of different lengths, and business days are counted one day at a time.
- Days between = (later date − earlier date) ÷ one day, plus 1 if the end date is counted
- Calendar difference borrows days from the previous month and months from the year, exactly as an age calculation does
- Business days = every Monday to Friday in the span, minus the holidays you enter
- Weeks = total days ÷ 7
What the result means
Days between is a plain subtraction, optionally counting the end date. The calendar difference expresses the same span in years, months, and days, and the business-day count includes only Monday to Friday, minus holidays you enter.
Common mistakes and assumptions
- Forgetting whether your contract counts the final day — that is the include-end-date option.
- Expecting the business-day count to know your local public holidays; you enter those.
- Reading months as fixed 30-day blocks; they follow the calendar.
Worked example
From 1 April 2026 to 15 July 2026, not counting the end date, with 1 holiday in the range.
- 1Day count = 105 days between the two dates.
- 2Calendar difference = 3 months, 14 days.
- 3That span contains 75 weekdays and 30 weekend days.
- 4Removing one public holiday leaves 74 business days.
- 5105 days is 15 whole weeks exactly.
Frequently asked questions
- Should I count the end date?
- It depends on the rule you are applying. Deadlines and interest periods usually exclude the end date; notice periods, rentals, and stays often include both. Switch the option and use the count your contract implies.
- Which days count as business days?
- Monday through Friday. Public holidays are not detected automatically because they vary by country, state, and industry, so enter how many fall in your range.
- Why is the month count not just days ÷ 30?
- Months are between 28 and 31 days long. The calendar difference walks real months, so a span from 31 January to 28 February is one month, not 0.93.
- Can the end date be earlier than the start date?
- Yes. The dates are ordered internally and the gap is reported as a positive span, with a note telling you the order was reversed.
Disclaimer
This calculator returns estimates based only on the values you enter. It does not account for taxes, financing terms, local regulations, or conditions specific to your operation, and it is not accounting, legal, tax, or investment advice. Confirm any figure that carries real cost before you rely on it.
Calculations run entirely in your browser and the numbers you type are never sent to us or stored. Read how Answerivo calculators are built.
Formulas and worked example last reviewed .