Hi dlen,
currently timeframes with no events are not displayed, but if my memory is not deceiving me, recently one of our club members worked on that and could make them to be displayed even with no events. Anyway as a club member we'll give you the best support we could to make it happen

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I'm not sure about overlapping events showing exactly as in the image shown, but it might be doable as well.
Maybe Geraint can give you his opinion about this