In this paper we present three scheduling mechanisms that are manipulation-proof for closed systems. The amount of information that each user must encode in the mechanism increases with the complexity of the mechanism. On the other hand, the more complex the mechanism is, the more it maintains the privacy of the users. The first mechanism is a centralized, calendar-oriented one. It is the least computationally complex of the three, but does not maintain user privacy. The second is a distributed meeting-oriented mechanism that maintains user privacy, but at the cost of greater computational complexity. The third mechanism, while being the most complex, maintains user privacy (for the most part) and allows users to have the greatest influence on the resulting schedule.