How to get options of existing XDSoft datetimepicker?

How to get options of existing XDSoft datetimepicker?

I am using:
http://xdsoft.net/jquery-plugins/demo/datetimepicker/

I create the datetimepicker like this:

$("#mydatetimefield").datetimepicker( {minDate: '2013/12/03', maxDate:'2018/12/31', disabledDates:['2015/12/25','2014/12/25'] };

The datetimepicker correctly shows the disabled dates as disabled. How can I get the disabledDates?

It does NOT exist, but something like this would be good:
$("#mydatetimefield").datetimepicker("getOption", "disabledDates");

I've tried:
theoptions = $("#mydatetimefield").data('xdsoft_datetimepicker').data('options');
but this only seems to return the default options.  theoptions.disabledDates is an empty array.

Any ideas how to extract the currently set options of a datetimepicker?