Re: is it possible to make an event last longer?
@itsgonbelit if it's possible to extend an event you'll see it in the top left hand corner of the screen on the timer/task list. As with active careers.
With prom in the HSY pack my Sims often get asked to attend the after party somewhere, I've found that happens with high friendships with other prom guests. You can use Social Bunny to max friendships if you have any difficulties and it helps with prom goals too. They stay out most of the night at the after party but it's not a goaled event.
The new Lovestruck pack added the option to extend dates in conversation too. That's handy when not all dating goals are completed. Also for the first time, it can be extended when the unplayed Sim asks your Sim if they would like to extend the date. (I don't know if that has been added to non Lovestruck dates though as I have the pack).
Hope this helps!