The time selectors are not part of the jQuery datepicker widget, they are added by the form.
What is it you are trying to do?
If you want to set a default time then you would probably need to set those chosen options using JS on dom ready, but what time do you want to set them to?
Well when I was setting the value of the datetime field with that shortcode it set the time as well. All I want to do is set the time of that field to the current time. I should be able to sort it out from here, cheers.