Hello, does anyone know if it's possible to to script a datepicker in client event script, to execute on button click? For example, a jQuery Datepicker?

you should be able to to have a client script since NS has jquery ref and trap whatever event the calendar of choice throws or native onclick and then execute a button script via jquery. DOM walking is not popular I see on here but should be safe until a massive overhual of netsuite ui.