- preg_match: documentation ( source)
<?php
$news = ['date'=>'01.01.1970 в 00:00'];
$date_parts_match = preg_match('~(\d+)\.(\d+)\.(\d+)[^\d]+([\d+]+)~ui',$news['date'],$date_parts);
echo $date_parts[1],'-',$date_parts[2],'-',$date_parts[3],' / ',$date_parts[4];