[CoolGuySteve]

If they're using a javascript 53bit int representation for the seconds (or an int64_t cast down to a javascript big int) then it's a Y142711K problem, by which point the Imperium of Mankind will hopefully have settled on a more robust format.

[wmil]

The tech-priests will have lost the ability to fix it.

[freeone3000]

That's how we ended up with the 2038 problem!

[toyg]

I expect Slaanesh and friends will manage to sabotage that somehow.