Date: daysAfter() / daysBefore()

src/org/hwo/datetime/Date.java

@@ -116,14 +116,31 @@ public class Date {
 		return false;
 	}
 	
+	public int leapsSinceAC(){
+		return (year / 4) - (year / 100) + (year / 400);
+	}
+	
+	
 	private static int[] daysInMonth = { 31,28,31,30,31,30,31,31,30,31,30,31 };
 	public int getDaysInMonth(){
-		int d = daysInMonth[ month - 1];
-		if (isLeapYear() && (month == 2))
+		return getDaysInMonth(month);
+	}
+	public int getDaysInMonth(int m){
+		int d = daysInMonth[ m - 1];
+		if (isLeapYear() && (m == 2))
 			d += 1;
 		return d;
 	}
 	
+	private int dayOfYear(){
+		int n = 0;
+		
+		for (int i=1;i<month;i++){
+			n += getDaysInMonth(i);
+		}
+		n += day;
+		return n;
+	}
 	
 	private static int[] Nmonth = {0,3,3,6,1,4,6,2,5,0,3,5};
 	
@@ -153,6 +170,18 @@ public class Date {
 		return ns % 7;
 	}
 	
+	public int getDaysAC() {
+		int dac = (365 * year) + leapsSinceAC();
+		dac += dayOfYear();
+		return dac;
+	}
+	
+	public int daysAfter(Date d){
+		return getDaysAC() - d.getDaysAC();
+	}
+	public int daysBefore(Date d){
+		return d.getDaysAC() - getDaysAC();
+	}
 	
 	
 }