获取用户注册日期

Question

所以我有一个mongoDB，它存储一个date.now变量，该变量返回当前日期。我希望用户数据库存储用户注册的日期。有什么方法可以做到吗？我假设在JS中使用Date（），但我不完全确定当我的所有数据库信息来自表单并且我不希望用户看到它时我会放在哪里。

var userSchema = new Schema({
    firstName: {type: String, required: true, validate: nameValidator},
    lastName: {type: String, required: true, validate: nameValidator},
    addressOne: {type: String, required: true, validate: addressValidator},
    addressTwo: {type: String, validate: addressTwoValidator},
    city: {type: String, required: true, validate: cityValidator},
    state: {type: String, required: true, validate: stateValidator},
    zipcode: {type: String, required: true, validate: zipValidator},
    country: {type: String, required: true, validate: countryValidator},
    registrationDate: {type: String, default: Date.now}

 });

    <input type="hidden" name="registrationDate"/>
    <script type="text/javascript">
        function getDate() {
            var today = new Date();
            var dd = today.getDate();
            var mm = today.getMonth()+1;
            var yyyy = today.getFullYear();
            if(dd<10){dd='0'+dd} if(mm<10){mm='0'+mm};
            var output = today.toDateString();
            return output
        }
        getDate();
    </script>

    var user = new User();
    user.firstName = req.body.firstName;
    user.lastName = req.body.lastName;
    user.addressOne = req.body.addressOne;
    user.addressTwo = req.body.addressTwo;
    user.city = req.body.city;
    user.state = req.body.state;
    user.zipcode = req.body.zipcode;
    user.country = req.body.country;
    user.registrationDate = req.body.registrationDate;