paraTimeline - issue with custom date range

I don't know how it works, but it really seems from the cell visualization that the date range is somehow calculated from some specific time of the chosen start day to a specific time of the chosen end day.

I created dataset with hourly timestamps for the purpose of the investigation and it seems that Custom date range takes all dates from the chosen date but after 9 AM.  And all datetimes until 9 AM of the chosen end date. Do you have any idea what could be causing this or how to work with it? I have tried to contact the developer of the visual, but it seems the email provided in pbiviz file of the visual does not exist.