Поправка первого кода(случайно свое написал)
$blogs_new = mysql_result(mysql_query("SELECT COUNT(*) FROM `blogs` WHERE `time` > '" . (time() - 86400) . "'"), 0);
$blogs_all = mysql_result(mysql_query("SELECT COUNT(*) FROM `blogs`"), 0);
echo '<div class="menu"><a href="blogs/">Блоги</a> ('.$blogs_all.''.($blogs_new ? ' / <span class="red">+'.$blogs_new.'</span>' : '').')</div>';