=COUPNUM(settlement, maturity, frequency, [basis])
COUPNUM
The function is used to calculate the number of coupon payments between two dates. It takes four arguments: the settlement date, the maturity date, the frequency of payments (in months or years), and the day of the month for payment.
=COUPNUM(DATE(2019,2,15),DATE(2029,1,1),2,0)
The following example returns the number of payments between February 15th, 2019 and January 1st, 2029, where payments occur every two months, on the first day of the month.
=COUPNUM(C6,C7,C10,C11)
The same result can be achieved by using cell references instead of the dates in the preceding example. Here, C6, C7, C10 and C11 are the cell references for the settlement date, the maturity date, the frequency of payments and the day of the month for payment respectively.
COUPNUM
The function ignores the time of day when calculating the number of payments. So, if the settlement date is 2/15/2019 10:00am and the maturity date is 1/1/2029 11:00am, the result will be the same as if the times were 2/15/2019 12:00am and 1/1/2029 12:00am respectively.
The COUPNUM function returns the total number of coupons that are payable between a given settlement and maturity dates, rounded up to the nearest whole number.