Days Between Dates Calculator
Calculate the exact number of days between two dates, including weeks, months, and time units.
Overview
The interval between two dates is the difference in elapsed days, which is not the same as the difference in calendar numbers. February lengths vary, month lengths vary from 28 to 31 days, and a span crossing 29 February gains a day that a naive month subtraction misses. Working in absolute days first and converting to weeks and months afterwards avoids every one of those traps.
Quick Presets
Total Days
天
Breakdown
岁, 个月, 天
Weeks
Months
Hours
Minutes
Seconds
How to Use
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1
Enter your values
Type your numbers into the Days Between Dates input fields.
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2
Adjust the options
Choose the units, method, or region that fits your situation, or apply a quick preset.
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3
Read the result instantly
The result updates as you type — no submit button, and nothing is sent to a server.
About
Inclusive and exclusive counting are the second source of disagreement. A hotel stay from the 1st to the 5th is four nights but five days; a contract term that begins on the signing date includes that day, while an interest period that starts on it usually does not. Legal and financial documents state which convention applies because the two differ by exactly one day in every calculation.
Day-count conventions in finance formalise the same choice: actual/365, actual/360 and 30/360 each produce a different accrual for the identical pair of dates.