DAYS360
Calculates the number of days between two dates based on a 360-day year (twelve 30-day months).
=DAYS360(start_date, end_date, [method])This static page keeps the function indexed for search, while the spreadsheet app handles interactive exploration and saved formulas.
What the function does
Overview
Calculates the number of days between two dates based on a 360-day year (twelve 30-day months).
The DAYS360 function is primarily used in financial and accounting calculations where a 360-day year convention is common. It determines the number of days between a `ate` and an `ate` assuming each month has 30 days and a year has 360 days. This method simplifies interest calculations and other financial modeling, particularly in bond calculations and other fixed-income instruments. The `ate` and `ate` should be valid Excel dates, either as serial numbers or text that can be parsed as dates. If `ate` is earlier than `ate`, the function returns a negative number. The optional `method` argument specifies the calculation basis: `FALSE` or omitted (U.S. (NASD) method) adjusts dates to ensure 30 days per month; `TRUE` (European method) handles month-end dates differently, specifically for the 31st of a month. Understanding the `method` argument is crucial for accurate financial modeling, as it can significantly impact the result depending on the specific financial standard being applied.
Quick reference
Syntax
=DAYS360(start_date, end_date, [method])Inputs
Arguments
Example: "1/1/2023"
Example: "3/1/2023"
Example: TRUE
Formula patterns
Examples
Calculating days using U.S. (NASD) method
=DAYS360("1/30/2023", "3/1/2023")Calculating days using European method
=DAYS360("1/30/2023", "3/1/2023", TRUE)Avoid these issues
Common Errors
#VALUE!
Cause: Either 'start_date' or 'end_date' is not a valid date that Excel can interpret.
Fix: Ensure both date arguments are valid Excel dates, either as serial numbers or text in a recognized date format.
#NUM!
Cause: The date arguments are valid but fall outside Excel's supported date range (e.g., negative serial numbers).
Fix: Provide dates within Excel's valid date range (January 1, 1900, to December 31, 9999).
Platform support
Compatibility
Available in Excel 365 and earlier versions.
Source: Microsoft Support
Common questions
Frequently Asked Questions
Calculates the number of days between two dates based on a 360-day year (twelve 30-day months).
ate: The first date, a date before or on the 'ate'. ate: The second date, a date on or after the 'ate'. method: [Optional] A logical value specifying the calculation basis. FALSE or omitted for U.S. (NASD) method; TRUE for European method.
#VALUE!: Ensure both date arguments are valid Excel dates, either as serial numbers or text in a recognized date format. #NUM!: Provide dates within Excel's valid date range (January 1, 1900, to December 31, 9999).