Do not order anything for same day delivery. Three separate times now, I have ordered something for same day delivery within a specific time frame. That time frame comes, and goes with no package being delivered... then, like clockwork, Amazon will say "Will be delivered by 8AM next day". Guess what? It doesn't show up. Then, Amazon will simply refund the purchase and apologize.
I'm not upset that I'm not getting my items (because they refund me & I can simply re-order), but upset that Amazon is making promises they cannot keep. If Amazon is not 95% confident (I understand things happen sometimes) that my package can be delivered within the timeframe specified, then why not be honest about that?
I would be much happier if I ordered something expecting 2-day delivery & got my item same day or next day. That would be a pleasant surprise. But it's frustrating to order something expecting same day (or 1/2/3 day, whatever), and have it show up late
I think if Amazon were to just shift the way they predict shipping speed, there would be a lot more happier customers. Amazon has been operating for so many years, and has gotten so big that you would think they'd have this stuff down to a science by now. Okay.. rant over.
TL;DR: Don't choose same-day delivery if you NEED something fast. There is a good chance it just won't show up and Amazon will refund the purchase.