Zeg nu nog eens dat het niet duidelijk is 
eventdate: the primary date to use for the event. If there’s a starting date (tblEvents.datefrom), that date will be used. For events without starting date, the event date becomes the embargo date (tblEvents.showfrom) , unless the creation date (tblEvents.datecreation) falls before the embargo date, or there was no embargo. In those cases the event date defaults to the creation date, which (by definition) is always filled in.sortdate: the sorting date for the event. By default this is the creation date, unless this falls before the embargo date, in which case the embargo date will be used.
Note that the sort date is not used in event lists or in the event calendar but only to sort the event in a list of news items, that aren’t necessarily all events.