Best month to actually give birth?

We’re starting to talk about TTC for our third and with our other two pregnancies we conceived our first month trying. I know it’s not guaranteed this time around but it’s what we’re aiming for. I didn’t give any thought to time of year with either of them but now with our oldest being in school it’s been on my mind.

Right now we have birthdays in February, May, and October and I’d rather not have our third child in those months. Our oldest was born in May and he got RSV at 7 months, it was terrifying and I can’t imagine a smaller baby getting it so I’m super worried about having a baby during peak illness season and especially with a school aged child — he brings all the yuck home. How do you even navigate all that school illness?