Time of day for solve

If possible, it would be handy to have a way to tag when I solved my puzzle. Either with a 'morning', 'afternoon', or 'evening' set tag. Or a clock time picker. I'd really like to be able to see data for what time of day I am fastest and when other people are their fastest. I would ideally like to see this as a graph in my 'Statistics' page. Knowing when I am fastest will be useful for pushing myself for practices at home. But equally, it gives me information that will help me if I am in a competition at an off-peak time. I can maybe have caffeine or sugar or something to help me through a slump. But I need to know when my slump is.