lib/Ext/field/DatePicker.js
function(format) {
        var value = this.getValue();
        return (Ext.isDate(value)) ? Ext.Date.format(value, format || this.getDateFormat() || Ext.util.Format.defaultDateFormat) : value;
    }
function(format) {
        var value = this.getValue();
        return (Ext.isDate(value)) ? Ext.Date.format(value, format || this.getDateFormat() || Ext.util.Format.defaultDateFormat) : value;
    }
Returns the value of the field formatted using the specified format. If it is not specified, it will default to
{@link #dateFormat} and then {@link Ext.util.Format#defaultDateFormat}.
@param {String} format The format to be returned.
@return {String} The formatted date.