Add getEastern member function

diff --git a/Util/IntlUtil.php b/Util/IntlUtil.php
index eb7711f49c8021ef3cc94c3df9b53ce1149c1ebc..b37169d7007d8c6708bc64d6f664a7568d7917ec 100644 (file)
--- a/Util/IntlUtil.php
+++ b/Util/IntlUtil.php
@@ -84,6 +84,46 @@ class IntlUtil {
                return $formatter->formatCurrency($number, $currency);
        }
 
+       /**
+        * Compute eastern for selected year
+        *
+        * @param string $year The eastern year
+        *
+        * @return DateTime The eastern date
+        */
+       public function getEastern(string $year): \DateTime {
+               //Set static results
+               static $results = [];
+
+               //Check if already computed
+               if (isset($results[$year])) {
+                       //Return computed eastern
+                       return $results[$year];
+               }
+
+               $d = (19 * ($year % 19) + 24) % 30;
+
+               $e = (2 * ($year % 4) + 4 * ($year % 7) + 6 * $d + 5) % 7;
+
+               $day = 22 + $d + $e;
+
+               $month = 3;
+
+               if ($day > 31) {
+                       $day = $d + $e - 9;
+                       $month = 4;
+               } elseif ($d == 29 && $e == 6) {
+                       $day = 10;
+                       $month = 4;
+               } elseif ($d == 28 && $e == 6) {
+                       $day = 18;
+                       $month = 4;
+               }
+
+               //Store eastern in data
+               return ($results[$year] = new \DateTime(sprintf('%04d-%02d-%02d', $year, $month, $day)));
+       }
+
        /**
         * Gets number formatter instance matching locale and style.
         *