When can a baby go 8 hours without feeding?

I was told that before 6 months the most a baby can go without feeding is 6 hours. I WANT TO CLARIFY I’m specifically asking about sleeping through the night. I still feed every 3-4 hours day time. Anyways I have a 4 month old who sleeps so beautifully which is amazing because it wasn’t always that way and it took work to get a bedtime schedule together. Literally if I let him he would sleep 8 hours which would be wonderful for me. My moms the one who told me 6 hours max because it’s not good for babies stomach so young. But I saw on Instagram a girl who’s account is specifically advice about babies she said her baby sleep like 9ish hours that night! And I think baby’s like almost 4 months maybe? What do you guys do for the night? When can baby finally sleep 8 hours straight?