Attach date and time with file name while uploading in php

I am uploading a file with date time but not happens, here is my code:

$time = date('Y-m-d H:i:s');
$filename = $time."-".$filename;
$store = "cvs/".$filename;
move_uploaded_file($tmpfilename, $store);

$time = date("d-m-Y")."-".time() ;
$filename = $time."-".$filename ;
$store = "cvs/".$filename ; 
move_uploaded_file($tmpfilename,$store);