There is a slight edge case when adding and subtracting a `Duration`
from a `SystemTime`, namely when the duration itself is finer/smaller
than the time precision on the operating systems.
On most (if not all non-Windows) operating systems, the precision of
`Duration` aligns with the `SystemTime`, both being one nanosecond.
However, on Windows, this time precision is 100ns, meaning that adding
or subtracting a `Duration` whose value is `< Duration::new(0, 100)`
will result in that method behaving like an addition/subtracting of
`Duration::ZERO`, due to the `Duration` getting rounded-down to the zero
value.
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