Stub Javascript Date()

dateStub.js

var oldDate = Date;
Date = function () {
    var args = arguments.length > 0 ? Array.prototype.slice.call(arguments) : [1293861600];
    if (typeof args[0] === 'string') {
        args = ["'" + args[0] + "'"];
    }

    return new Function('return new oldDate(' + args.join(',') + ');')();
}