DAYS360
Returns the number of days between two dates based on a 360-day year (12 months of 30 days), commonly used in financial calculations.
DAYS360(start_date, end_date, [method])Arguments
start_dateThe starting date.end_dateThe ending date.methodOptional. FALSE (or omitted) uses US (NASD) method. TRUE uses European method.(optional)
=DAYS360("1/1/2026","12/31/2026")Calculates days using the 360-day financial calendar.
=DAYS360(A1,A2)Returns the 360-based day difference between two dates.
=DAYS360(A1,A2,TRUE)Uses the European 30/360 calculation method.
- •Commonly used in accounting and bond interest calculations.
- •US and European methods handle end-of-month dates differently.
- •Not suitable for precise calendar day calculations — use subtraction (end_date-start_date) instead.
- •Both dates must be valid Excel dates.
- •Using DAYS360 for a precise, real-world day count instead of a genuine calendar subtraction - it's specifically designed for the simplified 30/360 financial convention, not actual elapsed days
- •Forgetting that the US and European methods handle end-of-month dates differently, so the same two dates can produce slightly different results depending on the method argument
- •Mixing up start_date and end_date order, which produces a negative result rather than an error - easy to overlook if you're not checking the sign
DAYSReturns the actual calendar day difference between two dates, unlike DAYS360's simplified 30-day-month assumption.YEARFRACCan also use a 30/360 day-count basis, offering a fractional-year alternative to DAYS360's raw day count.DATEDIFCalculates real calendar differences in years, months, or days, a more precise alternative when actual elapsed time matters.Does DAYS360 give the actual number of days between two dates?
No, it uses a simplified financial convention where every month is treated as having 30 days - for the true calendar day count, subtract the dates directly or use DAYS instead.
What's the difference between the US and European methods in DAYS360?
They handle dates that fall on the 31st of a month, or the last day of February, differently - the European method always treats the 31st as the 30th, while the US method has additional end-of-month adjustment rules.
Why is my DAYS360 result negative?
start_date is later than end_date - DAYS360 doesn't raise an error for this, it simply returns a negative count, so double-check the order of your arguments.
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