Also, calendars aren’t exactly the same everywhere. If you say “let’s work out sat and sun every other week”, in the US this results in a calendar where you have every other weekend off. On an EU calendar, this results in working out every week. Or something like that, it was pretty entertaining when my friend pointed out how subtly shifting the calendar to start on a different day results in a very different work out plan.

But back to counting. In the EU, if you go to the first floor, you’d call that the second floor in the US. It has one floor in the EU, but two in the US. I have no idea if this is the same thing or just a mistake. But there are some interesting assumptions in this thread!