Model's date sent to server as millisecond string, not number

Is the intended behavior of a model's proxy to write a string instead of a number when the dateFormat is U (milliseconds since 1970) or timestamp (Unix timestamp, same as U)?

I ask, because my server expects a date as milliseconds as number, but the model's proxy is sending milliseconds as string, so the POST request is failing:

This proxy code:

Code:

writer:{
            type:'json',
            allowSingle : true,
            dateFormat: 'timestamp'
}

Produces these post values in console:

Code:

• start: "1395979200"


• stop: "1414728000"

When I add a transform function to the writer to do a parseInt on the date values, the values are sent as numbers:

Code:

writer:{
            type:'json',
            allowSingle : true,
            dateFormat: 'timestamp', //this is being sent as a string
            transform: {
                fn: function(data, request) {
                    data.start = parseInt(data.start);
                    data.stop = parseInt(data.stop);
                    return data;
                }
            }
}

Produces this POST request:

Code:

• start: 1395979200


• stop: 1414728000

Model's date sent to server as millisecond string, not number