Just watch out for President's Day. McMurray shipped my chicks on the Saturday before President's Day last year. 6 died in the box out of 27 from combination of cold and delay.
I wasn't pleased but I think they would have been fine if not for the holiday, so try to avoid that situation for yourself. Good luck and have fun with them.
If you do purchase around a Monday holiday it can sometimes work to your advantage... When buying a mixed order you get some of the rarer birds since people shy away from that date.
AND remember that post offices are closed but the mail is still being sorted in there! I know I worked for a rural post office as part time postmaster and you can call and check on your order anytime. Your local post office can give you the phone no. of the sorting plant and you can call there early a.m. to see if they have them and go pick them up at the back door. Believe me they WANT to have the chicks picked up
Remember that mail is worked and sorted 24/7 so be aware that a postal person can answer the phone...
Our driver would put the chickens in front seat of truck instead of back where the mail was....
Even if you order from a hatchery in the south there's no telling how many cold areas they have to go thru to get to you. I would wait. As Miss Prissy stated, the keets won't be available until May and by then the temps should be better for shipping.