There are many ways to answer the questions «Который час?» and «Сколько времени?» The easiest way is also the strangest way to the American way of thinking, using an ordinal number followed by the word час hour:

The hour from twelve to one is considered the first hour of the twelve-hour clock, so if someone in response to «Который час?» answers «Первый час», then that means it's somewhere from 12:00 to 12:59. If the answer is «Двенадцатый час», that means it's between eleven and twelve. Sometimes it's okay to fudge a bit in translating them into English:

That probably seems like a weird way to tell time, but I bet it harkens back to the days of sundials. Sundials aren't like digital watches that easily display minutes and seconds. You glance at the sundial and you can most quickly tell what the hour is, and you see what number the shadow is moving toward, so just naming the hour was probably a fairly practical thing for people to do.

Other entries dealing with time are soon to come. Look for them under the categories "Time phrases" and "What time is it" and "At what time."