Time for latest tweet

Currently I’m using this slip of code to grab the latest tweet of a user on Twitter. I’m looking for a command that will also grab the time it was tweeted at. This is probably a very simple line of code, I’m just not fluent in PHP yet. This is what I have so far…Thanks

<?php
                            $username = "Username"; // Your twitter username.
                            $prefix = ""; // Prefix - some text you want displayed before your latest tweet.
                            $suffix = ""; // Suffix - some text you want display after your latest tweet.
                            $feed = "http://search.twitter.com/search.atom?q=from:" . $username . "&rpp=1";
                            function parse_feed($feed) {
                            $stepOne = explode("<content type=\"html\">", $feed);
                            $stepTwo = explode("</content>", $stepOne[1]);
                            $tweet = $stepTwo[0];
                            $tweet = str_replace("<", "<", $tweet);
                            $tweet = str_replace(">", ">", $tweet);
                            return $tweet;
							}
                            $twitterFeed = file_get_contents($feed);
                            echo stripslashes($prefix) . parse_feed($twitterFeed) . stripslashes($suffix);
							?>