Frosh week officially starts on Sept 3rd, but Sept 3 and 4 are just move-in days and events within the residence buildings. Campus-wide events start on Sept 5th. You can find the schedule here:
http://studentsuccess.mcmast er.ca/...s/146/112.html
And online purchasing is closed for MacPasses, but the website says:
We will be doing a very limited amount of SAME DAY SALES, on Saturday September 3 at noon, first come first serve, and on Sunday September 4 beginning at 9am, first come first serve, in the Student Success Centre, Gilmour Hall rm 110.
So make sure to get there early!