1. A method of creating and updating schedules, the method comprising: receiving, by a processor, a plurality of initial events associated with a plurality of entities; generating, by the processor, an initial schedule in a single calendar that includes the plurality of initial events; receiving, by the processor, a plurality of subsequent events; applying, by the processor after receiving the plurality of subsequent events, selection criteria to each initial event of the plurality of initial events to identify a subset comprising all initial events of the plurality of initial events that satisfy the selection criteria and are, therefore, to be kept within the single calendar; the applying, wherein a consequence of at least one criterion of the selection criteria applied to each initial event depends on the identity of the entity of the plurality of entities associated therewith; and generating, by the processor, an updated schedule in the single calendar that includes the subset of the plurality of initial events and the plurality of subsequent events and does not include initial events of the plurality of initial events not included within the subset of the plurality of initial events.