For 31 day's I would suggest purchasing an annual pass, may seem silly to buy a year long pass for just a month but since Disney's tickets max out at 10 days its actually much cheaper and easier to do so versus buying 3-4 magic your way passes per person that expire 13 days after first use and possibly mixing them up. 31 days is a long time, so take your time and enjoy the parks, you will have a l