When should I pack????????????????///?

I am leaving in 22 days to go on my summer vacation I will be there for about 2 months. I don't know when to pack everyone says the day before and that sounds smart because I will need to pack all my clothes because I don't have very many but when should I pack the extra stuff I am going to take. I always forget some things so when should I pack them so I don't forget. I am leaving on a friday and I am homeschooled so I can stay in my PJ's all day but when should I pack?? This is in the wrong section but it is because no one is ever in packing and preparation so you can't get any answers. It is in Parenting because I would like to know when your kids pack when you pack what is a good timeline for it.