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Date difference calculator

Days, weeks, months and working days between two dates.

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About this tool

Count the days between two dates, and see the same gap expressed as weeks, whole months, years months and days, hours and minutes, plus the number of Monday-to-Friday working days it contains. The arithmetic is done on calendar dates in UTC, so a range that crosses a daylight-saving change is not quietly one day out — a mistake that catches out a surprising number of online calculators. Nothing is sent anywhere, so contract dates and case dates stay on your machine.

Helpful answers

Using this tool

Why are there two day counts?

Because both are right for different questions. “Days apart” is the plain subtraction: 1 March to 2 March is one day. “Counting both dates” includes the first and last day, so the same range counts as two days.

Are public holidays excluded from working days?

No. Working days here means Monday to Friday. Holidays differ by country, state and industry, and a calculator that guessed would be wrong more often than it was right, so the tool states its rule instead.

How are months counted?

By advancing whole months from the first date and measuring what is left, so 15 March to 15 May is exactly two months. Where the day does not exist in the later month — 31 January to 28 February — the end of that month counts as a whole month, which is the convention date libraries and most contracts follow. Months have different lengths, so any single number of days for “a month” would be a fiction.

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