they will flower naturally on their own. one can speed up the process with force flowering using a box or something that'll block all light but it's a real pain keeping up with the time table manually. like neo said, you will need a fast flowering strain like durban poison, early girl and others...check the breeder's info and also overgrow's strainguide for what will work in your area. some may recommend lowryder or another auto-flowering strain too but i won't...i prefer the non-ruderleris strains. but there are some excellent auto-flowering strains out there too...years ago we had "sticky #3" that was highly sought after and most excellent flavor and potency. C99 would also probably work for you...it is an extremely short term flowering sativa (not an auto-flower) that will finish close to your date, maybe a tad early. but worth trying if you can afford to experiment with several different strains...which i recommend anyway.

good luck and get em started indoors a month before planting outside if ya can...