> You don't want to store two dates for an event. It's easier to store the start time of the event and a duration for the event. Frankly speaking you could sto

> You don't want to store two dates for an event. It's easier to store the start time of the event and a duration for the event. Frankly speaking you could store all three (begin, end, duration) and just use whatever you need for different purposes. Just introduce a single point of entry/update that keeps alternative representations in sync.