It depends what kind of business... there are all sorts of weird and wonderful accounting / financial calendar inventions like the 4-4-5 calendar, fiscal years ending in June, bond day count conventions like 30/360, etc.
I do take your point though. I've always found it quite surprising just how universal various arbitrary/western things are like, as you say, the western gregorian calendar, seconds/minutes/hours, SI units for measurement. In a world with so many unintelligible languages and disagreements, you'd think there would be more folks out there doing, I dunno, a 10 day week, or some non-hour/minute system, etc.
My partner's place of employment has a fiscal year ending June 30th and a use-it-or-lose-it vacation policy. We are hikers who live in the northeastern United States, which means we're inevitably planning a backpacking trip to use up her remaining vacation at the height of black fly[0] season.
We did a three week thru-hike of the Long Trail in 2022. We had shelters almost entirely to ourselves north of the AT/LT split at the Inn[1] because nobody hikes the LT in June/July if they can avoid it.
I think people save them up towards the end of whatever year just because you aren't sure if you're going to need them for medical leave or a sudden family trip or something. As you get close to the end you get more certain that you won't use them on something else and can plan a block trip
It’s 2569 here in Thailand. Used on basically everything official and often more as on many sites, apps, etc, switching the language between English and Thai will alternate between the Thai year and Georgian year.
I do take your point though. I've always found it quite surprising just how universal various arbitrary/western things are like, as you say, the western gregorian calendar, seconds/minutes/hours, SI units for measurement. In a world with so many unintelligible languages and disagreements, you'd think there would be more folks out there doing, I dunno, a 10 day week, or some non-hour/minute system, etc.