Translating Drupal 8 Calender

I am trying to install the calendar Module in Drupal 8 for hebrew language and for some reason even main things like weekdays are not automaticly translatet like in Drupal 7 . I would like to know if there is a way how to translate- in the translationfiles of Drupal the calendar translations are only for Drupal 7. And while styling for RTL Layout i don t find the way to make the text right aligned in the table. That was fine in Drupal 7. I use the Bartik theme meanwhile because of its great support for RTL so i guess its not the theme itself. thank you Susanne