problem displaying axis values in flex chart

I have a value object 开发者_运维知识库something like this

public class Data
{

    public var date:Date;
    public var value:int;

            ...

    public function get formattedDate():String
    {
        return date.getDay()+"."date.getMonth()+"."+date.getYear();
    }

}

When I use the 'date' field for the category axis everything is fine but when I change that to the 'formattedDate' it doesn't work (the axis has no labels). Any ideas why this isn't working?

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Watch types.

When you use date you get Number type result.

When you use formattedDate you get String type result.

You have to return Number type also using formattedDate.