academic papers or legal?

In terms of meaning, "it's time" and "it is time" are essentially the same. They both convey the idea that a particular moment has arrived or that something should happen now or in the near future.

To be more particular, The only difference between the two phrases is their contractions. "It's" is a contraction of "it is", so "it's time" is just a more informal or casual way of saying "it is time." The contraction "it's" is commonly used in spoken English and in informal writing, while "it is" is more formal and is often used in formal writing, such as academic papers or legal