Rick - I've been trying to look up details on this, and it seems some take a different root. For example:
//creating expiration date
var now = new Date();
now.setTime(now.getTime() + 1000 * 60 * 60 * 24 * 365)
document.cookie = "name=" + escape(phrase) + ";expires=" + now;
Notice the 1000 (milliseconds) in there. (I've seen some examples with and without the 1000 ms, so I don't know...)
Full explanation
here