Hi! I don't think it matters very much, as long as you realize that you are supplementing with solids not replacing a milk feeding, that is, offer just as much milk/formula as you always have (especially at first, because its best to start very slowly with solids). For both of my kids, I started solids at dinner time, offering them just before I normally fed milk (e.g. 6:30 solids, 7:00 milk). Worked great for my first son. For my second, I still offer solids first (because it fits in my family's dinner schedule better), but sometimes he gets too fussy and I need to stop, nurse him, then go back to the solids. Both of my sons LOVE eating, so starting solids was a lot of fun for me. I hope it is for you too!