Form and rules
How it works
Use had better + base verb for strong advice, often when there may be a negative consequence.
The contraction is 'd better: You'd better leave now.
Negative form: had better not + base verb.
Use It's time + to-infinitive for a neutral statement: It's time to go.
Use It's time + subject + past simple to suggest the action should already happen: It's time we went.