Whats with the maintenance schedules?

I know every month they have a server clean up which usually helps out with ping and game response time. But I was almost psyched out that we weren't going to be able to play for 6 hours straight 3 days in a row around a certain time. Luckily nothing has happened, yet. So what's the deal with the message?

"We will be performing network maintenance from 6AM until 12PM PST on 3/5, 3/6 and 3/7." I get that things seem to be clearly available and may only have a brief interruption, but I wonder why it has to take 3 days and 6 hours straight at that. Perhaps they've set up a certain scheduled for a maintenance crew to fix up/upgrade some network gadgets in the server room. That's my best guess. Unless it has something to do with what's been happening to a lot of people lately.

There's clearly a difference between server and network maintenance. So I question what that could possibly mean.