Think on this. Studies done by universities have shown that fall aeration even very late is very beneficial to the lawns in most cases more benefical then spring aeration. The soil has all the fall to work with freeze and thaw and is therefore more loose in the early spring for the early root growth. Also the fert will work down all winter and be there early for the early growth. My experience has been that if I aerate late in Nebraska and fert with it the lawns jump out earlier than if I do not. That means earlier mowing by usually two weeks and the customer is happier with a greener lawn sooner. Now think on this You have more time in the fall. Studies have shown that you can aerate cool season grasses as late as the first hard freeze (study done at Michigan State) So this gives you the whole entire fall to get the aerations done...Not a tight window like in the spring..Here is what I do
New aeration customers are done in the spring. I aerate and fert at the same time also I have the lawn mowed extra short. The customer will see nearly instant results. In days the damaged grass springs back nice and green...After I have them sold on the benes of aeration I move them to the fall where I have more time. We all win and the customer is happy, the bank is happy, my dog is happy and spring is not such a rush.