Apo's have come and gone for soo many cultures and civilizations...it isn't even funny.
Math though....math is eternal...
Best way of finding out is as has been suggested set the calendar to Dec. 31 2036 and see...
I doubt much will happen.
not for the nxx0 devices anyway.
The interaction of so much other tech and programs that will be affected and those spinoff ramifications...that ...however...that is another matter completely.
Not much can stop that literal internal countdown that unix is heading towards...I'm sure someone will come up with something sometime.