I don't use online calendar, sync.to Thunderbird. Thunderbird is really moving along, but leaves a lot to be desired.

I also use Thunderbird's calendar and wish it was better: it's very obvious that it's a plugin coded in JS. I keep lo-fi and use .ics files and git as my core tool, and in the end I wrote a minimal python tool to render (read-only) HTML of my schedule https://github.com/danstowell/calendrino/ #calendar