When my DS was 6 months, I gave him solids once a day for a week, then
it increased to twice a day, and so on. I wanted him to be accustomed
to the new food by letting the rest of the day with breastmilk or
formula. And it also a good way to check whether he had food allergies
or not.

When I noticed that he was OK, then the schedule becomes 3 times a day.
It was when he was 7 months old, if I'm not mistaken.

Good luck, dear
- aurora -
http://aurora.insparenting.com