1. A method for calendar-based coverage monitoring, the method comprising: receiving a coverage rule defining at least one covering entity for performing an activity for a covered entity and at least one period of time during which the at least one covering entity is to perform the activity; monitoring individual calendars for the at least one covering entity and detecting a change in at least one of the calendars; determining whether the change causes the coverage rule to be violated; and in response to determining that the change causes the coverage rule to be violated, automatically generating a notification indicating violation of the coverage rule, wherein at least one of the preceding actions is performed on at least one electronic hardware component.