At what age did you start to give your LO 3 meals a day?

My 7 nearly 8 month old son has 4 bottles a day sometimes 5 but not often, and 2 meals breakfast and dinner, he will have a rusk on most days too. I haven't given him 3 meals a day yet as he is happy as he is, but I'm pretty sure he will be dropping a feed soon I will then replace with a 3rd meal, but he loves his milk and is gaining weight steadily so I am happy with his routine for the moment. My 1 1/2 year old was on 3 meals a day at his age but she barely had any milk as she turned against it once she turned 6 months, so I made sure she had yogurts and anything containing calcium.