Use the COUPDAYS function to return the number of coupon days in the coupon period that contains the settlement date.

COUPDAYS(Settlement, Maturity, Frequency[, basis])

 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: 1 for annual 2 for semi-annual 4 for quarterly Basis Number The basis determines how many days exist in a year. A full year has: 360 days when basis US (NASD) 30/360, Actual/360, and EUR 30/360 are used 365 days when basis Actual/365 is used 365 or 366 days when Actual/Actual is used 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: 1 for Actual/Actual 2 for Actual/360 3 for Actual/365 4 for European 30/360 Learn about the conventions used to calculate the day count for basis.

The COUPDAYS function returns a number.

• 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 (semi-annual), 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).

COUPDAYS

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: a settlement date of 01/15/2018 a maturity date of 01/15/2021 a frequency of 1 (annual) a basis of 1 (Actual/Actual) 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: the settlement date is 01/15/2018 the maturity date is 01/15/2021 the frequency is 4 (quarterly) 90