How long do babies use 3m clothing and 3-6m clothing?

Judy 🐰👓 • 🌞 24 years old, proud Navy wife. expecting our first baby in June 💙 👶🏽 IG@gls.xoxo
How long do babies use 3m clothing and 3-6m clothing? Is it pretty much the same thing? How much did your babies weight?