Saving API call result to a collection but recieving errors while setting up a SimpleSchema

I have a Meteor method which does an API call, then the response of the call is saved to the users collection. I'm using the Collection2 package with my project and I'm a little bit lost setting up my SimpleSchema for this.

Here is what the JSON response looks like from the API call:

[{"keyword":"2i","url":"http://example.com","title":"Example","timestamp":"2016-11-05 08:54:42","ip":"00.00.00.000","clicks":"2","user":"HweoSCY2ujscjJ9Zl"},{"keyword":"2j","url":"http://example.com","title":"YouTube","timestamp":"2016-11-06 02:11:18","ip":"00.00.00.000","clicks":"1","user":"HweoSCY2ujscjJ9Zl"},{"keyword":"2k","url":"http://example.com","title":"YouTube","timestamp":"2016-11-08 03:35:12","ip":"00.00.00.000","clicks":"0","user":"HweoSCY2ujscjJ9Zl"}]

Here's currently how I've been able to save this data to the users collection:

Meteor.users.update(Meteor.userId(), {
  $set: { 'shortURLs.URLS': result.data }
});

This works and looks like this in the db:

My issue is that I'd like to have a SimpleSchema setup for this so that the "timestamp" will be saved as a Date instead of a String, but everytime I try and create a schema for it I just receive errors like "After filtering out keys not in the schema, your modifier is now empty". I have tried a lot of different variations to try and make it work but none of them have been successful, here's just currently where it's at:

Schema.ShortURLs = new SimpleSchema({
    shortURLs: {
        type: Object
    },
    'shortURLs.$': {
        type: Object
    },
    'shortURLs.$.keyword': {
        type: String,
        optional: true,
        label: "Keyword"
    },
    'shortURLs.$.url': {
        type: String,
        optional: true,
        label: "URL"
    },
    'shortURLs.$.title': {
        type: String,
        optional: true,
        label: "Title"
    },
    'shortURLs.$.timestamp': {
        type: Date,
        optional: true,
        label: "Timestamp"
    },
    'shortURLs.$.ip': {
        type: String,
        optional: true,
        label: "IP"
    },
    'shortURLs.$.clicks': {
        type: String,
        optional: true,
        label: "Clicks"
    },
    'shortURLs.$.user': {
        type: String,
        optional: true,
        label: "User"
    },
});

This is then attached apart of a User Simple Schema:

...
shortURLs: {
    type: Schema.ShortURLs,
    optional: true
},
...

And I have that attached to the users collection:

Meteor.users.attachSchema(Schema.User);

I don't think there's an issue with how I have it attached as I have other SimpleSchemas setup the same way and they're working fine, I believe the issue is how I have this particular one written. Any help here would be extremely appreciated.

You need to define the shortURLs type in the Meteor.users collection as type: [Schema.ShortURLs], i.e. a list of type Schema.ShortURLs

Schema = {}
Schema.ShortURLs = new SimpleSchema({
    keyword: {
        type: String,
        optional: true,
        label: "Keyword"
    },
    url: {
        type: String,
        optional: true,
        label: "URL"
    },
    title: {
        type: String,
        optional: true,
        label: "Title"
    },
    timestamp: {
        type: Date,
        optional: true,
        label: "Timestamp"
    },
    ip: {
        type: String,
        optional: true,
        label: "IP"
    },
    clicks: {
        type: String,
        optional: true,
        label: "Clicks"
    },
    user: {
        type: String,
        optional: true,
        label: "User"
    },
});

Schema.User = new SimpleSchema({
...
  shortURLs: {
      type: [Schema.ShortURLs],
      optional: true
  },
...
});

...

Meteor.users.attachSchema(Schema.User);