4PM is the closing time, on a Sunday, unfortunately. I think it recommends this in the Bible, but I couldn't say for sure.
Does anybody ever try and shock the supermarket checkout staff? I started doing this a few years ago. If I needed condoms, I'd purposely go and buy them from the supermarket. I'd buy the biggest pack they had (generally a 12 pack, sometimes ribbed for her pleasure) and then buy a fair amount of beer. And that's all. Once, I stayed a girlfriend's place and forgot to bring a toothbrush so I bought one as well. I then choose the checkout person I thought it would be the easiest to get a reaction out of. These days, I'm running out of ideas. I started buying squirty cream etc and that combination usually gets a smile and occasionally a comment, but not always. People are too open-minded.