Is there a way to Object.freeze() a JavaScript Date?

Question

According to MDN Object.freeze() documentation:

The Object.freeze() method freezes an object: that is, prevents new prop

Answer 1

The accepted answer is actually flawed, I'm afraid. You actually can freeze an instance of any object including an instance of Date. In support of @zzzzBov's answer, freezing an object instance does not imply the object's state becomes constant.

One way to prove that a Date instance is truly frozen is by following the steps below:

var date = new Date();
date.x = 4;
console.log(date.x); // 4
Object.freeze(date);
date.x = 20; // this assignment fails silently, freezing has made property x to be non-writable
date.y = 5; // this also fails silently, freezing ensures you can't add new properties to an object
console.log(date.x); // 4, unchanged
console.log(date.y); // undefined

But you can achieve the behaviour I suppose you desire as follows:

var date = (function() {
    var actualDate = new Date();

    return Object.defineProperty({}, "value", {
        get: function() {
            return new Date(actualDate.getTime())
        },
        enumerable: true
    });
})();

console.log(date.value); // Fri Jan 29 2016 00:01:20 GMT+0100 (CET)
date.value.setTime(0);
console.log(date.value); // Fri Jan 29 2016 00:01:20 GMT+0100 (CET)
date.value = null;       // fails silently
console.log(date.value); // Fri Jan 29 2016 00:01:20 GMT+0100 (CET)