Regarding the datepicker: The code for the datepicker looks for all elements with that given class WHEN THE PAGE IS LOADED. It attaches AT LEAST an onclick event handler to each such element.
When you add a row dynamically, you don't notify the date picker that there is a new element with that class, so it doesn't have a chance to attach the needed onclick handler.
Cloning the HTML of the elements does *NOT* clone the event handlers for those elements.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.