datepicker edit does not make button show

datepicker edit does not make button show

I have a form with a textfield and a datepicker. If a textfield is editted then a "save" button appears:

I make the button appear like this: 

$('.rowsaver').on('keyup',function() {
    $('.btnvanish').show();
});
$('.rowsaver').on('keypess',function() {
    $('.btnvanish').hide();
});

I also use a datepicker i have a field with class 'rowsaver' and 'datepicker':

And this is the datepicker code:

$(function() {
    $( ".datepicker" ).datepicker({ dateFormat: "yy-mm-dd" });
    $( ".selector" ).datepicker({ dateFormat: "yy-mm-dd" });
  });
     
The datepicker works, but if i edit the date the "save" button does not appear.

How is this possible and does anyone have a idea how to fix this?