Abstract: A mechanism and method for calendaring a plurality of events such as scheduling the operation of interrelated machines which perform a process flow. Future time is divided into segments, called buckets, of increasing length. The first two buckets are of the same size and each of the following buckets twice as large as its preceding bucket. The first bucket slides so as to always cover a specified length of time following the current time. Events scheduled in the calendar is added to the appropriate bucket, depending on how far in the future it is to take place. When the current time equals the scheduled time for an event, then that event is removed from the bucket where it resides. When a bucket has become empty because all events have been removed from it, the events in the following bucket are distributed over the two buckets preceding it.