for me, late Autumn evenings when the moon is up, especially during a Harvest Moon; foggy mornings, afternoons, or evenings when the fog is so thick you can't see more than a couple feet in front of you; and during a light misty rain.
(yeah, sounds bleak, but in reality those times are amazing. They have a beauty all their own, even in the bleakest like fog and rain...especially if you have a good imagination!)
What time is "Hammer Time"??? (does anyone really know/ does anyone care?)