Will this birthday party take an hour and a half, or two hours?

[YunoYurbubson]

Ds's 4th birthday party.

About 6 children.

A swim in our pool (have got lots of floaties and fun stuff)
Hot dogs. Jelly.

Birthday cake.
Pinata.
Party bags.

Shall I say 3.30 - 5.00 or 3.30 - 5.30?

Depends how warm it is! I think probably 2hrs would be safer, as by the time they get changed, swim, get changed again then have cake etc, could easily be over an hour. I presume parents are coming too with that age group, so they need time to get changed etc. When I take 2.5yr old swimming I usually reckon on 1:5hrs. Just have some toys on hand for them to play with, especially if some get bored/cold in pool before others. Either way I would finish at 5, some children don't eat much at parties /are greedy and will want to eat at home before bedtime. 5:30 is a bit late, plus they might start getting grumpy.