I have a person that died on 25 Sep 1853 at the age of 66 y 11 m 25 d. When I plug this in all I get is Sep 1786 for the birth...no day. When I put in a date of birth, date of death and try to get it to work out to the age at death of above it skips from 66 y 11 m 24 d to 66 y 11 m 26 d.
I also plug in the same at the Ancestry website and it gives me a phony date of 31 Sep 1786!
So Roots Magic and Ancestry both have bugs regarding this. I am guessing it should be 30 Sep 1786???