[WorldMaker]

Y2K38 is a "standard Unix functions" problem. I don't think the surprises this time are going to be mission critical software doing date math, I think the surprises are going to be "non-mission critical apps" that "don't do date math" where it is not that "no one wants to risk touching it" but more "no one has thought to touch it in years because it isn't mission critical and it's just some random thing in the stack".

Case in point, this article's pointing a finger at fontconfig. Who considers fontconfig mission critical software? fontconfig has been open source forever, is it just "too boring" that no one has bothered to do a Y2K38 audit on it? It probably doesn't even really care about dates for the most part, so maybe no one even realizes it needs a date math audit? Multiply that across the very long tail of Unix apps and libraries since 1970. That's the weirder risk of Y2K38 than Y2K: the huge amount of "non-mission critical"/"non-date math" code that potentially exists in every Unix-derived tool. (With all non-Windows OSes in common usage today themselves being Unix-derived, that's a lot of surface area.)

Y2K was looking for everything that did date math with varchar(2) or 2-digit BCD. Those were needles in haystacks certainly, but the needles were sharp enough to know when you found one. Y2K38 is looking for subtle differences in (mostly) C macros and C library function calls and making sure that time_t structs are appropriately sized for modern platforms. That almost sounds to me more like looking for particularly colored straws in a haystack.