init commit

api/app/Utils/Calculations/Week.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Utils\Calculations;
+
+class Week
+{
+    public static function sub(int $minuendo, int $subtraendo): int
+    {
+        $result = $minuendo - $subtraendo;
+
+        return $result < 1 ? 7 - abs($result) : $result;
+    }
+
+    public static function sum(int $firstPortion, int $secondPortion): int
+    {
+        $result = $firstPortion + $secondPortion;
+
+        return $result > 7 ? $result - 7 : $result;
+    }
+}