I have a habit of staying up late on Sundays when I shouldn't, probably because subconsciously I don't want the weekend to end. As a result I tend to feel very tired by Monday evening and usually don't game as much as I would on another day.
I'm starting to think though that I might be missing out by not playing on Mondays more often. The first time I noticed this was when I happened to spend a Monday in Borovia, where the map was being positively depopulated by all the hardcore players running around and slaughtering everything in sight to quickly get their weekly done, and when the big heroic on Yester Hill popped, I never saw Thornspur die so quickly before.
This week I observed the same phenomenon when I quickly jumped into Omu one more time, the Tyrant came up, and people killed everything so quickly that I actually got the achievement for keeping all the beast cages intact. Plus at the end, where the Tyrant is supposed to run away when his health gets low - well, it did still happen because the script commanded it, but strictly speaking his health had already hit zero a long time ago. Just finding a good group to tag along with makes this kind of content so much easier.