I'm using regex to get date time from a string in proper format. 
if string is `2/12/2013 2 : 31 AM` then i use below code to remove spaces before and after `:` to get `2/12/2013 2:31 AM`

```
$dtTime = preg_replace('/(\s+\:\s+)/', ':', $dtTime);

```

But what to do when string is `2/12/2013 2 31 AM` to get `2/12/2013 2:31 AM`?
I tried to use below code but not worked

```
$dtTime = preg_replace('/[^\/0-9](\d+\s\d+)/', ':', $dtTime)

```

Note that date may be separated by `/` or `-`

Purpose of above code is to get date and time separately from a string by: 

```
    $dtime = strtotime($dtTime);
    $rtime = date('H:i:s',$dtime); // 08:50:05
    $rdate = date('Y-m-d',$dtime);

```