If it is just about what time of day I'm the most creative I might say it usually is from night til late at night especially during full moon.
Otherwise my creativity seems to depend on more factors. During good times when I've got all I need and are pretty happy in general I'm not all too creative and if so it's mostly when I couldn't do anything anyways. During bad times however my creativity and productivity gets quite a boost, I only sleep like 4 hours per day, stay at home most of the time, start working on old abandoned projects or start new ones and even get them done, its like some sort of perk activating. Right now my creativity is pretty much on a peak, I've built an engraving chisel, a couple miniature weapons (a cutlass, an axe and a blunderbuss), I started working on a flintlock pocket pistol which makes fairly good progress (all of these projects have been built from scratch in my garage), I also finished an animation which I haven't for years and it even turned out better than all of my old animations.