Methods, systems, and computer program products for calendar-based coverage monitoring are disclosed. According to one aspect, a method includes 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 multiple covering entities is to perform the activity. Individual calendars for the at least one covering entity are monitored and a change in one of the calendars is detected. It is then determined whether the change causes a threshold criteria to be met, and in response to determining that the change causes the coverage rule to be violated, a coverage warning notification indicating a potential for violation of the coverage rule is automatically generated.