Past bikeshedding, there's also the long list of myths programmers believe about time[1] and the crowd-sourced followup[2]. Pendulum inherits from datetime in the stdlib, but I'm unsure how well either of those address the issues raised (or even if it's possible - some need to be addressed by the code that uses pendulum/datetime).
Nobody has a good solution to leap seconds. 86400 seconds = 1 day is nailed into too much software. The problem is serious enough that some operations, including high frequency trading, are stopped around a leap second.