Morning
I'm not a fan of the middle part. Early morning, shortly after midnight, that's usually a good time. Late morning, just before lunch, that's okay, too. It's the middle section that's lame. It's the time when I stumble like a zombie for the coffee, snarl at furniture, and sit bleary eyed in front of a monitor wondering why I'm not still sleeping.
I would probably do that anyway, but it's especially bad first thing in the morning. The elf in the next cubicle just shrieked, "Good Morning!" Now, I have to refill my mug while he tries to stop screaming.