The two bolded sections contradict each other making this one impossible. For the first part to be true, the last part would need to be the younger the person the later the month. Your answer has a difference of 11 years and 11 months.
Your original post states that the first person is born this year. That implies that that person will be the oldest one and the others will be born after.
A world where everything is taken literally. A fork in the road means there is actually an eating utensil in the middle of the road. Like in the Phantom Tollboth if you have read it.