I do find there's a lot of benefit to flexibility though. If I'm in the zone at the end of day, and don't have anything else to do that night, I'll often work a

I do find there's a lot of benefit to flexibility though. If I'm in the zone at the end of day, and don't have anything else to do that night, I'll often work an extra ~2 hours (or until I feel like I've lost it.) But on the flip side, I will also leave early on a night where I have a lot to do outside work.