Returns a number from 1 to 7 identifying the day of the week of a date..
| Name | Type | Description |
| arg1 | number | Is a number that represents a date. |
| arg2 | number | Is a number: for Sunday=1 through Saturday=7, use 1; for Monday=1 through Sunday=7, use 2; for Monday=0 through Sunday=6, use 3. |