What I would love to see in the month view of the calendar is a button or checkbox that you can click to show that you have watched the show, instead of having to "drill down" to that show's watch list to click it there. That would be so very welcomed!
Cheers!
It will require you to download an extension for your browser, but you can give this a try...
https://openuserjs.org/scripts/gazza911/Mark_From_Calendar
It will add an eye icon which you can use to mark episodes as watched - I'm not likely going to be making any more changes on it though (but I did realised that I hadn't released the update despite coding it a long time ago)
We don't have this in the monthly calendar because we didn't want to make that view too cluttery, but we do offer this for all Premium members in the weekly calendar: https://www.tvmaze.com/features/tv-episode-calendar. From there, you can mark an episode as watched/acquired/skipped with one click :)
