Syntax
COUPDAYS(Settlement, Maturity, Frequency[, basis])
Arguments
Argument  Data type  Description 
Settlement (required)  Date  The bond settlement date: The date the bond is traded to the buyer. 
Maturity (required)  Date  The bond maturity date: The date when the bond expires. 
Frequency (required)  Number  The number of coupon payments per year. Enter:

Basis  Number  The basis determines how many days exist in a year. A full year has:
US 30/360 is the default basis for COUPDAYS. It can also be specified by entering 0. To use a different type of day count basis, enter:
Learn about the conventions used to calculate the day count for basis. 
The COUPDAYS function returns a number.
Constraints
 The settlement and maturity dates must be valid dates between 01/01/1900 and 12/31/2399.
 The maturity date must be later than the settlement date.
 The frequency must be either 1 (annual), 2 (semiannual), or 4 (quarterly).
 The basis, when specified, must be either 0 (US (NASD) 30/360), 1 (Actual/Actual), 2 (Actual/360), 3 (Actual/365), or 4 (EUR 30/360).
Calculation engine functionality differences
Excel equivalent
Related Anaplan functions
Examples
This example shows how the number of days in the coupon period that contains the settlement date can be calculated when a basis is specified.
Formula  Description  Result 
COUPDAYS(DATE(2018, 1, 15), DATE(2021, 1, 15), 1, 1)  This formula uses:
 365 
In this example, the number of days in the coupon period that contains the settlement date is calculated without specifying a basis. As a result, the basis defaults to US 30/360.
Formula  Description  Result 
COUPDAYS(DATE(2018, 1, 15), DATE(2021, 1, 15), 4)  This formula uses:
 90 