In my current project, timing is particularly important because my protagonist is a potter. My initial estimates of the time required to throw, dry, fire, glaze and re-fire pottery were too short. After I adjusted the pottery schedule, I noticed other time-related issues. Some events happened too quickly, while others were unrealistically delayed.
A calendar provides a simplified view of a novel on a single page. I can trace the narrative arc without getting bogged down in details. A calendar is also a useful tool for tracking pacing. I can easily see how many events happen on a given day and how much time elapses between events.