compareDates
Compares a CustomCalendar instance with a date represented by the given year, month, and dayOfMonth.
Returns a negative integer if the calendar is before the given date, zero if they are equal, and a positive integer if the calendar is after the given date.
Return
A negative integer, zero, or a positive integer as described above.
Parameters
calendar
The CustomCalendar instance to compare.
year
The year of the date to compare with.
month
The month of the date to compare with.
dayOfMonth
The day of the month of the date to compare with.