10% of the year is not a sensible way to measure your error. If I ask “When did X happen?” and you answer 2000 CE when the real answer was 2020 CE, there’s a sense in which you are more wrong than if you answered 300 BCE while the real answer was 500 BCE. Even if you don’t think this, you probably don’t think that the sensible target should be narrower closer to 0 BCE.
Whereas you are in a meaningful way about as incorrect if you say 10 km when the real answer is 11 km as if you say 1 m when the real answer is 1.1 m
10% of the year is not a sensible way to measure your error. If I ask “When did X happen?” and you answer 2000 CE when the real answer was 2020 CE, there’s a sense in which you are more wrong than if you answered 300 BCE while the real answer was 500 BCE. Even if you don’t think this, you probably don’t think that the sensible target should be narrower closer to 0 BCE.
Whereas you are in a meaningful way about as incorrect if you say 10 km when the real answer is 11 km as if you say 1 m when the real answer is 1.1 m
On reflection yep “within 50 years” or something like that would have been better.