Common Lisp Time Handling: The LOCAL-TIME Solution

This paper delves into the complexities of time handling in Common Lisp and presents the author's solution: the LOCAL-TIME library. It traces the evolution of human time representation, from imprecise, context-dependent notations to precise scientific ones, highlighting the chaos introduced by political factors like daylight saving time. LOCAL-TIME uses an efficient fixnum-based representation, integrates world timezone data, and handles various time calculations and format conversions, thereby avoiding errors stemming from imprecise time representation—like the infamous Y2K problem.