Just order, pick delivery dates, done?

If so, how far in advance?

New business opportunity by any chance?

Haha something I'm super frustrated by. I'm just wondering if I'm crazy and the only one.

Doing it would be incredibly hard from a selling perspective -- but I want it as a customer :)

Not me. Sorry.
I mean, I do order gifts online. I certainly buy in advance of the day it's meant for. But it's the item itself and the price that mean everything to me, not some service whereby I can select my whole year's gift giving on 1 day, and enter the days it want them to arrive by. That would assume that I want to buy all my gifts from one vendor - never happens.