Had better … it’s time
Use
We use had better to give strong advice or to tell someone (including ourselves) what to do.
I‘d better go home. It’s getting late.
You‘d better tell mum what happened before she finds out.
Had better often implies that something negative will happen if something is not done and it often sounds like a threat or a warning.
He‘d better give me my money back or he’ll be in trouble.
You‘d better behave yourself if you don’t want me to get really angry.
Form
The word had is a past verb form, but the expression had better is only used to talk about the immediate future.
You‘d better call me soon. I’ll be worried.
After had better we need to use infinitive without to.
I‘d better take a look. (NOT I’d better to take)
Had better not (‘d better not) is the negative form of had better.
You‘d better not say a word about this.
I‘d better not forget.
In spoken English we normally use the short form ‘d better. And in informal speech, people sometimes say just better (without had).
You better go home.
I better get it right this time.
had better vs should
We often use should to give advice, to say that something is a good thing. And we use had better to express urgent advice or a warning, with bad consequences if you don’t follow it.
You should try the cake. It’s delicious.
He‘d better hurry up or he’ll miss the cake.
It’s time
We can use it’s time + to + infinitive or it’s time for someone + to + infinitive to say that someone should do something now or in the future.
It’s time for you to go to the doctor.
It’s time to take a decision.
We can also use it’s (about) time + subject + past simple to say that someone should do something now or in the future.
It’s time you went to the doctor.
I really think it’s high time you made a decision. We can’t go on like this any longer.
Note that we use the past in this form, but we are talking about the future.
We often use this form to complain or criticise.
It’s time you paid me what you owe me.
It’s about time you started looking for a job.