Returns the number of days in the specified month and year of the current era.
year An integer that represents the year. month A positive integer that represents the month.
The number of days in the specified month in the specified year in the current era.
For example, in System.Globalization.GregorianCalendar, Calendar.GetDaysInMonth(int, int) for February returns 28 in a common year or 29 in a leap year.