PHP get previous date

The following function gives the previous date of the date entered.

For date format: 2014-02-15

function prevDate($date)
  {
 $dateArray=explode('-',$date);
 $tomorrow = mktime(0,0,0,$dateArray[1],$dateArray[2]-1,$dateArray[0]);
 return date("Y-m-d", $tomorrow);
  }
 
  Usage of the function is as follows:
 
  $date = "2014-02-15";
 
  echo prevDate($date);
 
  Ouput is: 2014-02-14
 
For date format: 2014/02/15

function prevDate($date)
  {
 $dateArray=explode('-',$date);
 $tomorrow = mktime(0,0,0,$dateArray[1],$dateArray[2]-1,$dateArray[0]);
 return date("Y-m-d", $tomorrow);
  }
 
  Usage of the function is as follows:
 
  $date = "2014/02/15";
 
  echo prevDate($date);
 
  Ouput is: 2014/02/14