The INTEGER-OF-DATE function converts a date in the Gregorian calendar from standard date form (`YYYYMMDD`) to integer date form. The type of this function is integer.

## Usage

__FUNCTION__ __INTEGER-OF-DATE__ (`argument-1`)

## Parameter

`argument-1` must be an integer of the form

`YYYYMMDD`, whose value is obtained from the calculation (

`YYYY` * 10,000) + (

`MM` * 100) +

`DD`.

`YYYY` represents the year in the Gregorian calendar. It must be an integer greater than 1600.
`MM` represents a month, and must be a positive integer less than 13.
`DD` represents a day, and must be a positive integer less than 32 provided that it is valid for the specified month and year
combination.

## Returned Value

The returned value is an integer that is the number of days the date represented by
`argument-1` succeeds December 31, 1600 in the Gregorian calendar.