问如何动态设置jquery的datebox的minHour选项

EN

<input name="Date1" id="Date1" type="date" data-role="datebox" 
data-options='{"mode": "timebox", "closeCallback": "Date1Close();"}' /> 
...
<input name="Date2" id="Date2" type="date" data-role="datebox" 
data-options='{"mode": "timebox", "closeCallback": "Date2Close();"}' /> 

function Date1Close(){
    var startdate = $('#Date1').datebox('getTheDate');
    var minH = startdate.getHours() + 1;
    if (minH > 23) minH = 23;
    $('#Date2').datebox({"minHour": minH});
}

function Date2Close(){
    var enddate = $('#Date2').datebox('getTheDate');
    $('#Date2').datebox('setTheDate', enddate);
    $('#Date2').trigger('datebox', {'method':'doset'});
}