Idiom - In the nick of time

Idioms are common expressions people use to express a complete taught in few word. In the Nick of Time means at the last possible moment, just before is too late. It is also used when you want to say that you will do something in a very small amount of time, that you will finish it just in a few minutes, and won't take much effort on your part to do it. Examples, a) I will finish reading my chapter book in a nick of time, and then I will help you to do your work.
b) I forgot to write my report, but I will do it in a nick of time.
c) My brother is delayed, but he will be here in a nick of time.