UpdateDueDate class alternate example

UpdateDueDate.cls

// Note: VerifyDate seems to be quite obscure as a class name, so have changed it to UpdateDueDate, as this is what I understand the intent of the class to be.
// If updating a due date is not the intent, then I did not understand the intent of the code.

public class UpdateDueDate {

// Examples:
// if current date is 15th Feb and due date is 22nd Feb, return 22nd
// if current date is 3rd Feb and due date is 5th March, return the last date in February

	public static Date SetDueDateWithin30Days(Date currentDate, Date dueDate) {

		if(CheckDueDateWithin30Days(currentDate, dueDate)) {
			return dueDate;
		} else {
			return EndDateOfCurrentMonth(currentDate);
		}
	}
	
	private static Boolean CheckDateWithin30Days(Date currentDate, Date dueDate) {
		Date date30DaysFromCurrent = currentDate.addDays(30);
		if( dueDate > date30DaysFromCurrent ) { 
		  return false; 
		} else { 
		  return true; 
		}
	}
 
 
	private static Date EndDateOfCurrentMonth(Date currentDate) {
	  
		 ;; daysInMonth() returns the number of days in the month for a specific year & month.
		Integer lastDayInMonth = Date.daysInMonth(originalDate.year(), originalDate.month());
		
		Date endDateOfCurrentMonth = Date.newInstance(originalDate.year(), originalDate.month(), lastDayInMonth);
		return endDateOfCurrentMonth;
	}
 
}