Proper way to save date input data to Firebase with simpleLogin - angularjs

Question

I'm new to firebase, and I'm trying to add a Date Of Birth field to a form and save it to Firebase.
The input field in the form looks like this:
<label for="birthdate">Date of Birth</label>
<input type="date" id="birthdate" name="birthdate"
ng-model="user.birthdate" ng-required="true" placeholder="Last Name">
<p class="error validationerror"
ng-show="myform.birthdate.$invalid && myform.birthdate.$touched">
Birthdate is required</p>
Following a lynda.com tutorial, a working register function was created like this:
register : function(user) {
return simpleLogin.$createUser(user.email, user.password)
.then(function(regUser){
var ref = new Firebase(FIREBASE_URL + 'users');
var firebaseUsers = $firebase(ref);
var userInfo = {
date: Firebase.ServerValue.TIMESTAMP,
regUser: regUser.uid,
firstname: user.firstname,
lastname: user.lastname,
email: user.email
}
firebaseUsers.$set(regUser.uid, userInfo);
}); //add user
}, //register
I tried to simply add another birthdate: user.birthdate key:value pair to the end after email: user.email but that didn't work.
register : function(user) {
return simpleLogin.$createUser(user.email, user.password)
.then(function(regUser){
var ref = new Firebase(FIREBASE_URL + 'users');
var firebaseUsers = $firebase(ref);
var userInfo = {
date: Firebase.ServerValue.TIMESTAMP,
regUser: regUser.uid,
firstname: user.firstname,
lastname: user.lastname,
email: user.email,
birthdate: user.birthdate
}
firebaseUsers.$set(regUser.uid, userInfo);
}); //add user
}, //register
Nothing gets added to firebase for the birthdate.
If I do console.log("user.birthdate: "+ user.birthdate); right after var userInfo I can see the date that was chosen in the date picker... so I know its getting from the form into that register function.
I'm guessing that simpleLogin can only have firstname, lastname, and email?

Answer 1

A few helpful notes:
Firebase Simple Login has been deprecated by Firebase, in favor of the native authentication methods built into each of the Firebase client libraries. That said, it will continue to work.
Both Firebase Simple Login, and the native Firebase authentication, are merely delegated authentication services. That is, they only store credentials to make authentication easier in your app, but they do not store arbitrary user data. Your Firebase is the best play for that.
In the above example, writing to new Firebase(.../users) is writing to Firebase, not the authentication service, and you can write any arbitrary data of your choosing there. However, check the type of the birthdate that you're writing. Firebase leaf values can be of type string, number, boolean, or null - but it is likely that your datepicker might be returning an Object that just happens to toString() correctly.