Can not view any events/schedule in Calendar View, but in List view are working (Sharepoint 2013)

Hi...

I have a problem with my Calendar View in SP2013. It can not show any events/reservations/schedule I previously entered. The items shows normally when using regular List views.

I have tried to create a new Calendar view, but still, not showing anything at all.

This happens using any browsers (IE, chrome, FF)

This is the Calendar View:

This one is the List View (All events):

All views are default views after creating a calendar app. Not applying any filter or limit.

Please help me with this issue. Thank you...