A very similar thing happened to our first batch of chickens. We bought them from Murray McMurray hatchery on a Monday. They shipped out (supposed) next day air on Wednesday. Well the next Wednesday they showed up. Our post office actually called to tell us that they had taken a few dread ones out. Out of 25 little peeps we picked up 10, of which 3 survived the weekend. Murray McMurray replaced the dead chicks but, that doesnt make me feel better about 22 babies at all!!! The next batch did stay at the post office for the weekend but all but 1 made it. In total they were in the box for five days. They should be fine. I wish you the best. If we have learned anything its that you never ship chicks on a holiday weekend!