Friday is the second worse day.
we all want our eggs shipped 2-3 days to arrive in 2 days but most come in 3. Thursday shipping will normally mean 4 days. Friday shipping will mean 3 days but never 2. Any other day will give you a chance of 2 days but 3 at most if USPS does their job.
For eggs I am hatching in US I troll ebay on a sat eve looking for auctions that end early sunday morning (early enough that the west coasters are still in bed and the east coasters are in church) that have low bids. I will contact them and ask if they will ship monday. If they say yes I bid just above the lowest bid. if someone else really wants them I let then have them. I always check shipping costs first and look if the seller has other auctions. if they do, i ask for combined shipping. I dont get emotionally attached to the auction.
I get great bargains this way. They arrive wed/thurs. rest a day, hatch thursday or friday 3 weeks later. On CL on friday night and sold and gone by Sunday. I am not doing it to make money and just want to break even. I want to learn everything i can about this game and not deal with chicken poop in my apartment.