Elections in the UK are always on a Thursday — which as you say always feels a bit wrong (the other weird thing is that unlike in Australia where you can vote at any polling station within your electorate, in the UK you have a single specific polling station that you have to use — or you can do a postal or proxy vote, but those are the only options). The polling stations are open from 7am-10pm though, so it does give most people time to vote before or after work (and if you're in the queue at 10pm they have to keep the polling station open until everyone in the queue has voted).