4 since Sunday trading came in, not many people see it as a special day any more. When I was little, even if we weren't churchgoers, you still treated Sunday with respect. Other people's holy days are equally worthy of respect - Fridays for Muslims and Saturday for Jews.
I can't say I've kept to all of them, but I'm not saying which. There was a time in my youth when I had my eye on no 7 and no 10, combined...