Mapping model fields to Object with array values

Lets say I have an object that I'd like to map to a model:

Code:

{
    name: 'thisWeekObject',
    day: [
        {
            name: 'Sunday',
            value: 0
        },
        {
            name: 'Monday',
            value: 4
        },
        {
            name: 'Tuesday',
            value: 3.2
        },
        {
            name: 'Wednesday',
            value: 4.1
        },
        {
            name: 'Thursday',
            value: 1
        },
        {
            name: 'Friday',
            value: 0.2
        },
        {
            name: 'Saturday',
            value: 0
        },
    ]
}

In my model, I'm trying to do this:

Code:

Ext.define('MyProj.model.Week', {
    extend: 'Ext.data.Model',

    config: {
        fields: [
            {
                mapping: 'name',
                name: 'name'
            },
            {
                mapping: 'day[0].name',
                name: 'day0name'
            },
            {
                mapping: 'day[0]value',
                name: 'day0value'
            },
            {
                mapping: 'day[1].name',
                name: 'day1name'
            },
            {
                mapping: 'day[1].value',
                name: 'day1value'
            },
            {
                mapping: 'day[2].name',
                name: 'day2name'
            },
            {
                mapping: 'day[2].value',
                name: 'day2value'
            },

etc.

I've tried that, but unfortunately am still getting undefined for all my day fields.

Any suggestions?

I could use convert, but I need to be able to write to these fields as well.

Any help is appreciated.