How to delete national events from my calendar?

[Tine Dane]

I have a Huawei P8 Lite.
After I traveled to New Zealand and got a NZ simcard, these national days have automatically been added to my calendar..
I thought they would disappear when I put my own simcard back in, but they're still there and I can't si anything with them. There is no delete option or any other buttons whenever I click on the events.
I've tried to have a look which calendars are showing under my settings but there aren't any other than the phone's...
What do I do?

 

[B. Diddy]

Welcome to Android Central! Select one of the holiday events--does it show you which calendar account it belongs to? Can you edit the event?