Quote Originally Posted by John_Douglas View Post
But it's a bit easier in Russian because you have to use arithmetic to tell the time без двенадцати час
FYI без двенадцати час doesn't sound natural to me
you can say без десяти/пятнадцати/двадцати час but I would try to avoid saying без двенадцати час. If you need to be that specific you can say двенадцать часов, сорок восемь минут or just двенадцать сорок восемь

Also IDK if everybody knows, Russians live on 24 hour time unlike Americans living on 12 hour time and AM, PM, so it would be common for a Russian to say семнадцать часов for 5PM. However when you use без десяти час construction you need to use 12 hour time only, and say, for example без пятнадцати пять which could mean both 4:45AM and 4:45PM, depending on the context/time of usage