Hello,

When I'm logged as Super User, I can add event (on frontpage) wihout end date

Well, i'm surprised you are able to add an event in frontend without an end date for period when logged-in with super user access, as not related to access levels of the user...

The supposed behavior for all is no period possible if missing start or end date, and possible only start date if usage of the single dates.

So, i wonder how you could do this with super user access...

In all cases, for period, it is not possible today to add one without end date, and it is not supposed to be possible in all cases (the system may not work as expected currently if no end date for period...)
This will be possible in the future, with the new dates system manager planned for iCagenda 4 (start developement by the end of 2018).

Could you confirm you can with super user to submit a period without end date, and no single dates selected ? (as if possible, it may be a bug somewhere... by my test, i can't...)

Best regards,
Cyril