Anime Party problems?

Ok first of all I want to have a anime themed birthday party for my self and since my birthday is in December I want to have the party during the summer.

But the problem is the party will be on july 4th its the only time I can get family and friends together i think some of the older girls and teens might have some fun.

So here's the problem I need to know what all I can do for outdoors stuff.I was thinking about cosplay and some hide and seek maybe even some dancing while dressed in cosplay.And different fun things like that.

I was even thinking about doing a base color for everything.Like purple pink and black.I have some ideas already I just don't know how to get the guests into it.To want to have fun.

The problem is your birthday is in December and you want to celebrate it in July... That's the silliest thing I've heard on the Internet in a while.

Please tell me this is just a lame joke.

Is this party related in any aspect to japan? if not, i think you choose the wrong place to ask; you should go to an american cosplay forum and ask the same there.