How do I count occurrence of a day between two dates?

courtesy: kodejava

The code below helps you to find the number occurrence of a day between two specified date. The solution used below it to loop between the two dates and check if the weekday of those dates are equals to the day the occurrence we want to count.

import java.util.Calendar;

public class DaysBetweenDate {
public static void main(String[] args) {
//
// Month value in Java is 0-based so 11 means December.
//
Calendar start = Calendar.getInstance();
start.set(2000, 0, 1);
Calendar end = Calendar.getInstance();
end.set(2009, 11, 31);

System.out.print("Number mondays of between " +
start.getTime() + " and " + end.getTime() + " are: ");

int numberOfDays = 0;
int whichDay = Calendar.MONDAY;

while (start.before(end)) {
if (start.get(Calendar.DAY_OF_WEEK) == whichDay) {
numberOfDays++;
start.add(Calendar.DATE, 7);
} else {
start.add(Calendar.DATE, 1);
}
}

System.out.println(numberOfDays);
}
}