calendar views should be better
While integrating some project events in a calendar view I realized that each field must have it's own view. But I think this does not reflect the way people use calendar as they often group on the same calendar a lot of information from different sources in order to have a larger picture of the schedule.
After some discussion with Cédric we reached the conclusion that the calendar view should be defined almost like the graph view: with multiple axis for the events.
So the xml definition could change from
<calendar dtstart="...">
<field name="..."/>
</calendar>
to
<calendar>
<timeserie dtstart="...">
<field name="...">
</timeserie>
</calendar>