Cách dùng của It is time

Form:  It is (high) time + S + simple past

             It is (high) time + to-infinitive

             It is (high) time + for + O + to-infinitive


Meaning: đã đến lúc
Example:
    - It’s time we went.
    - It’s high time we left.
    -  It’s time to start.
    - It’s time for us to go.

Note: There is a slight difference in meaning between the form.

It is time + to-infinitive states that the correct time has arrived.

It is time + S + simple past implies that it is a little late.