description:
| Calculates the number of days from the beginning of the coupon period to the settlement date. |
syntax:
| COUPNUM( settlement, maturity, frequency, [basis] ) |
required arguments:
| settlement | The security settlement date is the date after the issue date when the security is traded to the buyer. |
| maturity | The maturity date is the date when the security expires. |
| frequency | For annual payments, frequency = 1; for semiannual, frequency = 2; for quarterly, frequency = 4. |
optional arguments:
| [basis] | The type of day count basis to use. |
