3rdparty: fix bug in when

3rdparty/when/When.php

@@ -621,7 +621,19 @@ class When
 		
 		if($interval == "month")
 		{
-			$this->try_date->modify('+1 month');
+			
+			$this->try_date->modify('first day of next month');
+			if((int) date('t', $this->try_date->format('U')) > (int) $this->start_date->format('j')){
+				$this->try_date->modify('+' . (int) $this->start_date->format('j') - 1 . ' day'); 
+			}else{
+				$this->try_date->modify('+' . (int) date('t', $this->try_date->format('U')) - 1 . ' day'); 
+			}
+			//$this->try_date->setDate(date('y/n/j', mktime(0,0,0,$this->try_date->format('j'), $this->try_date->format('n') + 1, $year = $this->try_date->format('Y'))));
+			//echo date('t', $this->try_date->format('U')) . '-' . $this->try_date->format('U') . ' ';
+			/*$month_day = $this->try_date->format('j');
+		$month = $this->try_date->format('n');
+		$year = $this->try_date->format('Y');*/
+		
 		}
 		else
 		{