Returns the number of whole workdays between two dates with custom weekend parameters.
| Name | Type | Description |
| arg1 | any | Is a serial date number that represents the start date. |
| arg2 | any | Is a serial date number that represents the end date. |
| arg3 | number | Is a number or string specifying when weekends occur. |
| arg4 | any | Is an optional set of one or more serial date numbers to exclude from the working calendar, such as state and federal holidays and floating holidays. |