I just set up khal recently with vdirsyncer to read my NextCloud calendar on the CLI. It took all of ten minutes, very easy to set up, configure to my liking, and use. Thank you very much!

I just set up khal recently with vdirsyncer too! But to read my Fastmail Calendar. I was a little surprised that the default khal config was not at all to my liking. Here's what I ended up with:

     [calendars]
       [[main]]
         path = ~/caldav/xxx/

       [default]
         highlight_event_days = true

       [highlight_days]
         color = "dark green"
         multiple = "dark red"

       [view]
         agenda_event_format={calendar-color}{cancelled}{start-end-time-style} {title}{repeat-symbol}{alarm-symbol}{description-separator}{reset}

       [locale]
       timeformat=%H:%M

I'd like a bit more colour diversity in the calendar, like different colours for birthdays. And maybe emoji markers (like for brithdays) in the view list.

Yes, I also modified timeformat and highlight_event_days (and highlight_days). In fact, I did quite a bit of other configurations as well. But the point I was making is that the system is usable after just a few minutes. If VIM is precedent, then we'll be configuring the poor thing for decades!