Nope, not literally true. While there are a bunch of simultaneous threads, the in-world action takes place over the course of months.
I enjoyed Nexus and enjoyed Crux as well. The sequel feels a lot less adventurous though, both from plotting (you can pretty much predict exactly where it's all going) and in terms of implications of the biotech (I don't remember a single clever/unobvious thing that happens with it - I know if I had a few months with that kind of nanotech, I'd have scripted some better macros at least). It also picks straight up from the end of the first novel, which was pretty disorienting for me because it had been months (a year?) since I had ripped through the original and it took a while to vaguely remember where that left off - I think the first is probably required reading for this one.
Crux also still suffers from "thrilleritis" and contains both dumb plotting and characters that should be smarter doing (really) dumb things.
Anyway, still worth a read but with tempered expectations IMO.