First, a debugging tip: while running your game in the desktop editor, click "HTML Tools" in the menu bar. In the window that comes up, click "Console", and you will see any JavaScript errors you have.
Now, on to the errors...
The main problem you have is that your setInterval line needs to have a paren after 1000:
setInterval(function () {storehours()}, 1000);
Second, in your if/else, you don't want the extra "var"s in front of the assignment. You want to use the variable that's already defined. (It turns out that JavaScript doesn't have block scope, so they will all resolve to the same variable anyway, but just from a conceptual point of view, it's wrong.)
Finally, a simplifying thought. If you move the setInterval below the definition for storeHours, then you can pass it directly.
Overall, then, here is an edited version.
function storehours() {
var furniturestoreopen;
var currentdate2 = new Date();
if (currentdate2.getHours() >= 8 && currentdate2.getHours() <= 20) {
furniturestoreopen = "open";
}
else {
furniturestoreopen = "close";
}
ASLEvent ("furniturestorehours", furniturestoreopen);
}
setInterval(storehours, 1000);
Edit: And just for grins, you can reduce it down to this:
setInterval(function() {
var hour = new Date().getHours();
ASLEvent ("furniturestorehours", (hour >= 8 && hour <= 20) ? "open" : "close");
}, 1000);