Consistency maintenance techniques used in networked multiplayer games require a tradeoff between the degree of consistency and the responsiveness to player commands. The choice of which technique is most appropriate depends upon the specific game situation. However, all techniques share the need to deal with time as well as with game state data. This can make implementing consistency maintenance techniques difficult. The solution is to have a programming model that is better able to deal with time. In this paper, we present such a programming model, timelines. Timelines allow for the explicit treatment of time and have been implemented as part of the Janus toolkit.