It's time

1) It is time + infinitive:
It's time to start the race. (現在是時候開始比賽了。)
It is time to take a break. (現在是時候休息一會兒了。)

2) It is time + for + object + infinitive:
It's time for us to start the journey. (現在是時候讓我們開始旅程了。)
It's time for you to go. (你現在是時候去了。)

3) It is time + for + noun:
It's time for breakfast. (現在是時候吃早餐了。)
It's time for a break. (現在是時候休息一會兒了。)

4) It is time + subject + past subjunctive:
It's time we went home. 
It is time he came here.
It is time the police took action.
It's time you made up your mind.

請留意，以上４種表達方法意思上不盡相同。

1-3表達的是做某事的時間到了。
而4不單表達做某事的時候到了，更暗示現在才做某事已經有點晚了 (It implies that it's a little late)。要更強調這個意思，可以說 It is high time （現在是非常適當的時候）: 
It's high time the government did something to address the issue of wealth inequality in Hong Kong. 
It is high time you stopped being foolish!
除了 it is time 和 it is high time，我們還可以說 it is about time（現在是差不多的時候）：
It's about time you started doing this on your own.
It's about time to leave.
It's about time we went home.
It's about time for you to get going.
It's about time the rich did something to help the poor.

留意以上第４類 (past subjunctive)，我們用過去式動詞 (simple past) 來說現在應該做卻還沒有做的事情，那過去式動詞不是真正的過去式(雖然寫法一樣)，乃是帶有假設意思的過去式，叫做 unreal past 或是 past subjunctive。