How to say it that when you look at the clock repeatedly as if you're waiting for something to happen quickly ?
To look forward to (something/doing something) is an idiomatic expression that can be used when you wish something to happen as soon as possible.
- to feel pleased and excited about something that is going to happen: I'm really looking forward to my holiday.
- [ + -ing verb ] She was looking forward to seeing the grandchildren again.
- I'm not looking forward to Christmas this year.
Prodigy's answer correctly identifies the person as "anxious". There are many things that could make a person anxious, including time delays.
You could also use "impatient", as it refers to someone who is upset by the need to wait. This is more specific.
In addition to that, US English has two idioms ("watching the clock" and "counting the seconds") to refer to people who are anxious for time to pass.
E.g.: "Jim is eager to leave the office today. He has been watching the clock all afternoon."