Love how the comments slightly start going off topic by discussing the Swiss cheese and then diverge completely towards the process of making Greek yogurt.

Anyway... This calendar fragmentation is a real problem, I've noticed that my most productive period was when I was working 5h/day and was forced to attend only the critical meetings and ruthlessly make time for deep work as Cal Newport calls it.

Nowadays with a very active 3yo child at home and a wife also working full-time remotely, we're working in 1-3 hour shifts and taking turns in taking care of the child so our calendars are perhaps the best example of Swiss cheese out there and I have no idea how to make it better.