$result = mysql_query("select lastLog from `table` WHERE user_id = '".$_SESSION['userID']."'");
while($row = mysql_fetch_array($result))
{
$last_login = $row['lastLog '];
}
if($last_login == date('d.m.Y'))
echo "its today";
if($last_login == date('d.m.Y',strtotime("-1 days")))
echo "it was yesterday";
else
echo 'it was '.$last_login;