This is actually so I can send you to a more appropriate Amazon (UK or US) because Amazon doesn't handle this themselves.

I built a script that uses your timezone to guess if you're near the UK and forwards you accordingly (this was prior to this chart existing). I linked the CB chart to it to avoid reproducing the same functionality.

I can possibly do this in a different way, but since it doesn't cost you anything ending up on Amazon I didn't really think anyone would be upset by it. I just did what was easiest and most useful.