THE 2038 PROBLEM

Summary from the TLDR Web Dev newsletter

Most Unix systems use a 32-bit signed integer to represent the number of seconds since January 1st, 1970. A 32-bit variable can only store integers up to 2147483647. Once system clocks tick past this at 03:14:07 UTC on January 19, 2038, their 32-bit signed integers will overflow to -(2^31) - this is the root of the “Year 2038 problem.”