Date :: subtract - Suntract date value
The function returns the date difference measured in days.
Return value: Set date from days ( int32 )
The function calculates the date from the number of days passed in iDayNum. The value must be greater than 0.
Implementation details
int32
Date  :: subtract ( odaba::Date &cDate )
The difference is calculated by subtracting days of the date passed from days for the current date.
- cDate
- Date
The date contains day, month and year, but not the time.

