Anytime you like as long you set a good example of party goer. And someone there is babysitting while you r not around.
when the kids leave home, sorry
After you have completed everything you need to do. Kids come first.
You'd need a babysitter that is ok with taking care of you child for a couple, maybe more, days. It is best if you don't take care of your baby during a hangover which is why the babysitter has to be ok with more than one day.
when you have a kid....its time for you to stop BEING the kid
Ask your parents.