Calendar showing hour per day in a wrong way

I created a content type and a custom format following the video tutorial : http://vimeo.com/6544779
Content type: Event
date field: Date

when i try to showup the granularity by day, the event shows only in the from date, not taking into account the to date. In other words, if the event starts at 20:00 and ends at 22:00, the event will be displayed in the calendar starting the 20:00 but does not take the 21:00 and 22:00 slot in the calendar.

Please view the explained screenshot below.

My use case is to make an event at each hour of the day, an event could take several hours depending on the from -> to date