Learn German: Es ist genau zwölf Uhr. - It is exactly twelve o'clock.

Uhr is used to mean "o'clock" when telling the time on the clock (like zwölf Uhr). Stunde means "hour" as a duration of time, like when you say a movie lasts one hour.

Is Es ist always used to state the time?

Yes! Just like in English where we say "It is twelve o'clock," German uses the neutral subject Es followed by ist to introduce the time.

Does zwölf Uhr refer to noon or midnight?

By itself, it could be either. In everyday spoken German, people rely on context to know which one you mean. If you need to be specific, you can add mittags (at noon) or nachts (at night). In official 24-hour schedules, midnight is often called null Uhr.

Can I leave out the word Uhr and just say Es ist genau zwölf?

Yes, in casual spoken German, you can often drop Uhr when it is a full hour, just like saying "It is exactly twelve" in English. However, keeping Uhr is the standard way you will practice first.