Unfortunately, no! You do have some control, though. Chicks are shipped on Mondays and Wednesdays. Smaller orders automatically ship USPS Express Mail, and larger orders of 15 chicks or more are shipped via Priority Mail service.
Why can't I get my chicks shipped on a different day of the week?
The short answer is that chicks wouldn't survive.
The long answer: Right before the babies hatch, they absorb their yolk sac, which sustains them with hydration and energy for their journey to you. But the yolk sac only provides about 2-3 days' worth of nutrition, so if we hatched the chicks on a Sunday night and didn't mail them to you until Wednesday, there would be no yolk sac left, and the chicks wouldn't last a day in the mail.
In nature, this is designed to help those chicks who hatch early to survive until mama hen is done sitting on the other eggs and can leave the nest to take all her babies to eat and drink. (She won't leave until she thinks everyone is done hatching!) Thank goodness for this neat evolutionary trick!