How to show 12 hour format in Titanium IOS time picker

I need a picker showing 12 hr format in IOS. format24 property is there, for android only :( My code is given below

Titanium.UI.createPicker({
    useSpinner : true,
    selectionIndicator : true,
    type : Ti.UI.PICKER_TYPE_TIME,
    value : defaultVal
});