Input on sleeping infant

Amanda

At what age do you allow your infant to wake you to eat instead of you waking them. — back story. My son was born 5 pounds 3 ounces 5 1/2 weeks early. I feed him every three hours except at night. I space it out first 4 hours but now 5. When can I let him wake me? He’s 9 pounds and 2 months old.