You cannot have two different functions with the same name. Try to change name the second function:
function showIt() {
document.getElementById("hid").style.visibility = "visible";
}
setTimeout(showIt, 6000); // 1000 = 1 sec
function showIt2 {
document.getElementById("hid2").style.visibility = "visible";
}
setTimeout(showIt2, 7000); // 1000 = 1 sec