Rewrite of calcDateDifferenceInYears function, because of invalid result for person with lifespan containing years divisible by 100 and not by 400. So for anyone born in XIX century who died in XX century, age was off by 1 year, unless full dates were used.
Rewrite of calcDateDifferenceInYears function, because of invalid result for person with lifespan containing years divisible by 100 and not by 400. So for anyone born in XIX century who died in XX century, age was off by 1 year, unless full dates were used.
I covered this border case in unit tests.