Added the Javascript implementation from Doomsday

ChaituVR · ChaituVR · commit eccfd80a8564 · 2017-10-12T16:03:54.000+05:30
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -24,13 +24,13 @@ Unfortunately, sometimes the bug can be only reproduced in your project or in yo
 
 1. Fork this repository.
 
-2. check the table in README.md file weather the algorithm is added. If not add a new row with the name of algorithm and create a new folder with a name of the algorithm. 
+2. Check the table in README.md file weather the algorithm is added. If not add a new row with the name of algorithm and create a new folder with a name of the algorithm. 
 
 3. Inside the folder create the folder for language you want to share. and add your code. 
 
 5. Commit
 
-6. update the README.md. check the language you have used in the table. (check emoji is ``:+1:`` ) 
+6. Update the README.md. check the language you have used in the table. (check emoji is ``:+1:`` ) 
 
 7. Commit, Push
 
diff --git a/Doomsday/JavaScript/Doomsday.js b/Doomsday/JavaScript/Doomsday.js
@@ -0,0 +1,44 @@
+
+/**
+ * Determines the day of the week using Tomohiko Sakamoto's Algorithm
+ * to calculate Day of Week based on Gregorian calendar.
+ */
+function dow(y, m, d) {
+    let t = [0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4];
+    y -= (m < 3) ? 1 : 0;
+    return Math.round(y + y / 4 - y / 100 + y / 400 + t[m - 1] + d) % 7;
+}
+
+/**
+ * Determines the day of the week using Tomohiko Sakamoto's Algorithm
+ * to calculate Day of Week based on Gregorian calendar.
+ */
+function dowS(y, m, d) {
+    switch (dow(y, m, d)) {
+        case 0:
+            return "Sunday";
+        case 1:
+            return "Monday";
+        case 2:
+            return "Tuesday";
+        case 3:
+            return "Wednesday";
+        case 4:
+            return "Thursday";
+        case 5:
+            return "Friday";
+        case 6:
+            return "Saturday";
+        default:
+            console.log("Unknown dow");
+    }
+    return null;
+}
+
+console.log(dow(1886, 5, 1) + ": " + dowS(1886, 5, 1));       // 6: Saturday
+console.log(dow(1948, 12, 10) + ": " + dowS(1948, 12, 10));   // 5: Friday
+console.log(dow(2001, 1, 15) + ": " + dowS(2001, 1, 15));     // 1: Monday
+console.log(dow(2017, 10, 10) + ": " + dowS(2017, 10, 10));   // 2: Tuesday
+console.log(dow(2018, 1, 1) + ": " + dowS(2018, 1, 1));       // 1: Monday
+console.log(dow(2018, 2, 16) + ": " + dowS(2018, 2, 16));     // 5: Friday
+console.log(dow(2018, 5, 17) + ": " + dowS(2018, 5, 17));     // 4: Thursday
diff --git a/README.md b/README.md
@@ -16,7 +16,7 @@ BreadthFirstSearch | :+1: | :+1: |  | :+1: |  |  |  |  |
 BubbleSort | :+1: | :+1: | :+1: |  | :+1: | :+1: |  |  | 
 DepthFirstSearch |  |  |  |  | :+1: |  |  |  | 
 Dijkstra's  | :+1: |  |  |  | :+1: |  |  |  | 
-Doomsday | :+1: |  |  |  |  |  |  |  | 
+Doomsday | :+1: |  |  |  |  | :+1: |  |  | 
 ElevatorAlgorithm | :+1: |  |  |  |  |  |  |  |  
 Fibonacci | :+1: | :+1: |  | :+1: |  |  | :+1: |  |
 FisherYatesShuffle | :+1: |  |  |  | :+1: |  |  | :+1: |
