Studying the source code mx.controls.CalendarLayout(which is used internally DateChooser):
var today:Date = new Date();
var currentMonthContainsToday:Boolean = (today.getFullYear() == newYear && today.getMonth() == newMonth);
it seems that you have no influence on this. You can, couse, extend / replace classes DateChooserand CalendarLayoutand override the corresponding functions.
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