there's a talk called "Time Programming Fundamentals" that sounds like it's about time machines, but it's actually about the incredibly complicated world of doing correct date and time math while respecting different calendars, time zones, changing civil time, daylight savings, and so on.
corvids
@BestGirlGrace stick to time machines. less complicated
@autistikai
"what's the hardest part of building a time machine?"
"all the goddamn calendar math"
@BestGirlGrace the real reason time travelers always have to ask a local what the date is
@autistikai "You there! What year is it? Who's president? I can't tell because my damn computer's stuck in the Julian calendar."
@BestGirlGrace ok but actually this is a legit justification for that trope and i. hate that fact. so much im gonna write a story with that plot point
@BestGirlGrace nah we've inadvertently studied plenty of history we already well familiar with that
@autistikai alternatively: forgot the "years divisible by 100 are not leap years unless they're also divisible by 400" rule
@BestGirlGrace or just whatever the fuck gaius was doing in rome
@autistikai happy to help! then you can move on to thinking about how, in some places, the calendar is missing a few days around when authorities switched the datekeeping system over