Added 15 solutions

Java/Introduction/Java Date and Time/Solution.java

@@ -0,0 +1,18 @@
+import java.util.Scanner;
+import java.time.LocalDate;
+
+public class Solution {
+
+    public static void main(String[] args) {
+        /* Read input */
+        Scanner scan = new Scanner(System.in);
+        int month = scan.nextInt();
+        int day   = scan.nextInt();
+        int year  = scan.nextInt();
+        scan.close();
+        
+        /* Create LocalDate instance */
+        LocalDate date = LocalDate.of(year, month, day);
+        System.out.println(date.getDayOfWeek());
+    }
+}