Mootools: Datepicker: invertAvailable with minDate doesn't work

I am using datepicker from mootools and I need to disable certain dates.

This is the code:

<script>
window.addEvent('domready',function(){
new Picker.Date(
$$('#ctrl_25'),{
'draggable':'false',
'pickerClass':'datepicker_bootstrap',
'useFadeInOut':'!Browser.ie',
'startDay':1,'titleFormat':'%d. %B %Y',
'availableDates':{2015: {5: [1,14]}},
'invertAvailable':'true',
'minDate':new Date(2015,3,24),
'toggle':$$('#toggle_25'),
'togglesOnly':false,
'positionOffset':{x:-197,y:-182},
'format':'%d.%m.%Y'});
});
</script>

      

        
        
        
      

    

now the problem is that "minDate" doesn't work if I use "invertAvailable" all days before this minDate can be clicked as well.

Is there a workaround?