I use jquery"s datepicker plugin

<div class="fs_title"></div>
        <input id="time_available" name="time_available" class="datepicker date_field" required>

        <div class="fs_title"></div>
        <input id="expiry" name="expiry" class="datepicker date_field" required>

after I choose the start date
how can I select the end date not less than the election start date?

$(function() {
  $( ".datepicker" ).datepicker({
    dateFormat:"yy-mm-dd",
    minDate: "0d", 
    changeMonth: true,
    changeYear: true
  });
});

he has a face minDate: "0d", which can be set, but I don"t know how to do it
is there a big god who can thank me