Zenkaikon memberships purchased at door are valid for the entire convention. However, depending on what day you purchase your membership, you may get a discount. For example, memberships purchased at door on Friday grant access for all three days (Friday, Saturday, and Sunday), so cost the full at-door membership rate. Memberships purchased on Saturday will grant access on Saturday and Sunday, and are discounted since Friday has already passed. Memberships purchased on Sunday are more heavily discounted, as Sunday is the last day of the convention.