1. A computer implemented method, performed by a computer system having one or more processors and memory storing one or more programs for execution by the one or more processors, the method comprising: presenting information representing a plurality of time-bounded events in (i) a first grid and (ii) a second grid, wherein (A) the first grid has a first size, and the first grid represents a first set of time-bounded events in the plurality of time-bounded events, and (B) the second grid has a second size smaller than the first size, the second grid represents a second set of time-bounded events in the plurality of time-bounded events, and the second set of time-bounded events includes a greater number of time-bounded events than the first set of time-bounded events.