I was reading a sentence and it kept my attention because it's like this.
Now it’s time you wrote a short composition.
The words that puzzle me here in the part that says "you wrote"
My question is: Is it a conditional?
It's the subjunctive. The indicative mood is not used because the speaker isn't saying that the event happened, but that it should happen.
Now it’s time [(that) you wrote a short composition].
No, it's not conditional, but modal. The bracketed element is a declarative content clause. Note that the subordinator that could optionally be added here.
The preterite form wrote expresses modal rather than temporal meaning, i.e. modal remoteness rather than past time.
The meaning is counterfactual. It entails that the situation is not yet in progress: "You are not writing a short composition, but should do so".