Brumas. I would like it earlier if possible. I find that by nine p.m. I am just getting in the mood to get my aching spine in to a horizontal positon.
But there are other considerations of course. I know some people don't get finished from work and having their evening meal until later, but about 19.30 hours or there-abouts would suit me better. I know it wouldn't make a ha'porth of difference to my wild guesses though.
Then of course there are the times you have to go on a happy holiday, or are busy doing other things. So don't go making hard and fast rules for yourself about times and things which you are going to find difficult to keep up with.
But I will be all for it if you do go ahead with it no matter what time. As jock1e said, maybe there are some of the old unsolved ones which might be recognised. He is pretty good at the game and may have missed those early ones.