Not anymore. From their FAQs:
When will my chicks arrive?
When shipped January – mid July - Chicks ship Monday, Tuesday and Wednesday of the week. When your order ships, we will send you an email with the USPS tracking number. You will be able to track your order online with the USPS tracking number.
When shipped late July – October - Chicks ship on Monday of the week. When your order ships, we will send you an email with the USPS tracking number. You will be able to track your order online with the USPS tracking number.
Depending on how rural you are, and how often your PO gets deliveries (some get them 3x a day) they could be there tomorrow. If not I would plan on them Wednesday.