Calendar view slow render time.

Have you added the filters for start and end date so only the currently viewed month is queried? I found without this, as soon as there were 40 or so items to show across the entire calendar, load times were noticeably slow.

There's some documentation here under #IMPORTANT:
https://www.drupal.org/docs/contributed-modules/calendar-view/recurring-... →

Also can you test the same view rendering but with a default display such as unformatted ?

Looking forward to hearing from you @StijnStroobants.

@iancawthorne indeed that did the trick. It was in the documentation, but missed it...

Thanks, I'll close this issue.