Pro-writing tip: if your story doesn’t need a number, don’t put a fucking number in it.
Nothing, I mean nothing, activates reader pedantry like a number.
I have seen it a thousand times in writing workshops. People just can’t resist nitpicking a number. For example, “This scifi story takes place 200 years in the future and they have faster than light travel because it’s plot convenient,” will immediately drag every armchair scientist out of the woodwork to say why there’s no way that technology would exist in only 200 years.
Dates, ages, math, spans of time, I don’t know what it is but the second a specific number shows up, your reader is thinking, and they’re thinking critically but it’s about whether that information is correct. They are now doing the math and have gone off drawing conclusions and getting distracted from your story or worse, putting it down entirely because umm, that sword could not have existed in that Medieval year, or this character couldn’t be this old because it means they were an infant when this other story event happened that they’re supposed to know about, or these two events now overlap in the timeline, or… etc etc etc.
Unless you are 1000% certain that a specific number is adding to your narrative, and you know rock-solid, backwards and forwards that the information attached to that number is correct and consistent throughout the entire story, do yourself a favor, and don’t bring that evil down upon your head.
I am inclined to agree with this, because I have just spent the past (unspecified number of months!) passing around an increasingly novel-length multi-branched thread of a tumblr post, analyzing a specific time-related number that a specific character mentioned in one scene in a 1982 movie and the significance it had for the entire fictional world.
Much thought was put into many things in that fictional world. But probably none was put into that number.
If I had written that script, I would be reconsidering my choices quite a bit in regard to that specific line.