From 17706489dce50603696b555cefa4179f93002029 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Combes?= <jerome@planningbiblio.fr>
Date: Tue, 21 Jun 2016 00:08:58 +0200
Subject: [PATCH] Use RRULE[WKST] and/or a default first day of week (USA=SU,
 Europe=MO)

---
 class.iCalReader.php | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/class.iCalReader.php b/class.iCalReader.php
index 4b88b21..b3fc642 100644
--- a/class.iCalReader.php
+++ b/class.iCalReader.php
@@ -39,6 +39,8 @@ class ICal
     /* The value in years to use for indefinite, recurring events */
     public /** @type {int} */ $default_span = 2;
 
+    /* The default first day of weeks */
+    public /** @type {string} */ $default_weekStart = "SU";
     /**
      * Creates the iCal Object
      *
@@ -46,7 +48,7 @@ class ICal
      *
      * @return Object The iCal Object
      */
-    public function __construct($filename=false)
+    public function __construct($filename=false, $weekStart=false)
     {
         if (!$filename) {
             return false;
@@ -58,6 +60,10 @@ public function __construct($filename=false)
             $lines = file($filename, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
         }
 
+        if ($weekStart) {
+	    $this->default_weekStart = $weekStart;
+	}
+	
         return $this->initLines($lines);
     }
 
@@ -395,6 +401,7 @@ public function process_recurrences()
                     $count_orig = (is_numeric($rrules['COUNT']) && $rrules['COUNT'] > 1) ? $rrules['COUNT'] : 0;
                     $count = ($count_orig - 1); // Remove one to exclude the occurrence that initialises the rule
                     $count += ($count > 0) ? $count * ($interval - 1) : 0;
+
                     $offset = "+$count " . $frequency_conversion[$frequency];
                     $until = strtotime($offset, $start_timestamp);
 
@@ -449,19 +456,30 @@ public function process_recurrences()
                     case 'WEEKLY':
                         // Create offset
                         $offset = "+$interval week";
+                        
+                        // Use RRULE['WKST'] setting or a default week start (USA = SU, Europe = MO)
+                        $weeks = array(
+			    'SA' => array('SA', 'SU', 'MO', 'TU', 'WE', 'TH', 'FR'),
+			    'SU' => array('SU', 'MO', 'TU', 'WE', 'TH', 'FR', 'SA'),
+			    'MO' => array('MO', 'TU', 'WE', 'TH', 'FR', 'SA', 'SU'));
+
+			$wkst = (isset($rrules['WKST']) and in_array($rrules['WKST'], array("SA","SU","MO"))) ? $rrules['WKST'] : $this->default_weekStart;
+                        $aWeek = $weeks[$wkst];
+                        $days = array("SA"=>"Saturday", "SU"=>"Sunday", "MO"=> "Monday");
+                        
                         // Build list of days of week to add events
-                        $weekdays = array('SU', 'MO', 'TU', 'WE', 'TH', 'FR', 'SA');
+			$weekdays = $aWeek;
 
                         if (isset($rrules['BYDAY']) && $rrules['BYDAY'] != '') {
                             $bydays = explode(',', $rrules['BYDAY']);
                         } else {
-                            $weekTemp = array('SU', 'MO', 'TU', 'WE', 'TH', 'FR', 'SA');
+			    $weekTemp = $aWeek;
                             $findDay = $weekTemp[date('w', $start_timestamp)];
                             $bydays = array($findDay);
                         }
 
                         // Get timestamp of first day of start week
-                        $week_recurring_timestamp = (date('w', $start_timestamp) == 0) ? $start_timestamp : strtotime('last Sunday ' . date('H:i:s', $start_timestamp), $start_timestamp);
+			$week_recurring_timestamp = (date('w', $start_timestamp) == 0) ? $start_timestamp : strtotime("last {$days[$wkst]} " . date('H:i:s', $start_timestamp), $start_timestamp);
 
                         // Step through weeks
                         while ($week_recurring_timestamp <= $until) {
@@ -490,6 +508,7 @@ public function process_recurrences()
 
                             // Move forwards $interval weeks
                             $week_recurring_timestamp = strtotime($offset, $week_recurring_timestamp);
+                            
                         }
                         break;
                     case 'MONTHLY':