When I started scrapbooking I still had childeen living at home. I preferred the late evening when everyone was out or sleeping. It was quiet and I could work uninterrupted. Also, we had just one computer and I had ready access to it. Now that I'm "retired" and the kids are grown and gone, I still prefer late evening. Mike is sleeping, Mom is watching tv in her room or sleeping, and I have no interruptions except a cat wanting outside occasionally.
Any time of day! In the summer I tend to do more scrapping during the day since I don't have my granddaughter here. When she is here during the school year, I do most of my scrapping at night.