The UK uses hand-counted paper ballots and often has multiple elections on the same day. You just have a separate ballot paper for each election. It's not unus

The UK uses hand-counted paper ballots and often has multiple elections on the same day. You just have a separate ballot paper for each election. It's not unusual to have votes for some combination of Member of Parliament, Regional Parliament, City Council, Local Mayor and Police Commissioner all on the same day. Members of the European Parliament too, until recently. It really doesn't take that long. Polls close at 10pm and first results can come out around midnight. Depending on how close the result is, the winner is often known around 6am the next day and the new Prime Minister can be in office by the afternoon.