Look at this timezone table
Why Madrid is not in this list? It has the third metro area in EU
Timezones are very tricky to implement. We use a library of timezones to get most of them, but it doesn’t actually have all. We know this isn’t the best case scenario and it is something that we’re looking to fix in the future, but it’s taking more doing than initially anticipated.
Sorry it’s not a full list at the moment.