Add two date helpers

- time_diff() to count the seconds between two datetimes
- secondsToString() to make a pretty string from seconds

application/helpers/MY_date_helper.php

@@ -35,5 +35,68 @@ if ( ! function_exists('mysql_now'))
 	}
 }
 
+/**
+ * Function to calculate date or time difference.
+ *
+ * Function to calculate date or time difference. Returns an array or
+ * false on error.
+ *
+ * @author       J de Silva                             <giddomains@gmail.com>
+ * @copyright    Copyright &copy; 2005, J de Silva
+ * @link         http://www.gidnetwork.com/b-16.html    Get the date / time difference with PHP
+ * @param        string                                 $start
+ * @param        string                                 $end
+ * @return       array
+ */
+if ( ! function_exists('time_diff')) 
+{
+	function time_diff($start, $end) 
+	{
+		$uts['start'] = strtotime($start);
+		$uts['end'] = strtotime($end);
+		if ($uts['start'] !== -1 && $uts['end'] !== -1) {
+			if ($uts['end'] >= $uts['start']) {
+				$diff = $uts['end'] - $uts['start'];
+				$diff = intval($diff);
+				return ($diff);
+			}
+		}
+		return (false);
+	}
+}
+
+/**
+ * Function to convert seconds to a pretty string.
+ *
+ * @author Karsten Heiken <karsten@disposed.de>
+ * @param integer $secs the amount of seconds
+ * @param boolean $includeseconds should seconds be appended to the string?
+ * @return string
+ */
+if ( ! function_exists('secondsToString')) 
+{
+	function secondsToString($secs, $includeseconds = false) 
+	{
+		$days = intval($secs / 86400);
+		$hours = intval($secs / 3600 % 24);
+		$minutes = intval($secs / 60 % 60);
+		$seconds = intval($secs % 60);
+		if (($minutes + $hours + $days) < 1)
+			return (sprintf(_('%d seconds'), $seconds));
+		else if (($minutes + $hours) < 1)
+			$string = sprintf(_('%d minutes'), $minutes);
+		else if ($days < 1)
+			$string = sprintf(_('%d hours, %d minutes'), $hours, $minutes);
+		else
+			$string = sprintf(_('%d days, %d hours, %d minutes'), $days, $hours,
+					$minutes);
+	
+		if ($includeseconds)
+			$string .= ' ' . sprintf(_('and %d seconds'), $seconds);
+	
+		return $string;
+	}
+}
+
 /* End of file MY_date_helper.php */
-/* Location: ./application/helpers/MY_date_helper.php */
+/* Location: ./application/helpers/MY_date_helper.php */