Syntax
COUPDAYBS(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 COUPDAYBS 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 before the settlement date can be calculated when a basis is specified.
Formula  Description  Result 
COUPDAYBS(DATE(2015, 1, 15), DATE(2018, 1, 31), 1, 1)  This formula uses:
 349 
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 
COUPDAYBS(DATE(2015, 1, 15), DATE(2018, 1, 31), 4)  This formula uses:
 75 