User:LeeA/Sandbox/Projects4

This page was created to help patrons learn to calculate a possible date of birth for their ancestors when none was given. Our decision is to keep it as it was with a minor addition:

Findings with the help of a third party: The problems with age and date calculators is that for some combinations there can be two answers either one of which can be correct depending on how age was calculated. We can't be 100% sure of which method was used.

Using the timeandate.com web site consider the following example:

Death date April 1 1870 and age at death 1 month 4 days. Put that information into the calculator and the result will be February 28 with an alternative date of February 25. What you need to understand is either one could be correct. 1.	Take Feb 25, add 4 days will give March 1 and add a month to get April 1 so February 25 could be the correct birth date. 2.	Take February 28, add a month to get March 28 then add 4 days to get April 1 so February 28 could also be the correct birth date So which way did your ancestor calculate age at death? The only way to be sure is to ask! Which we can't do. With many date and age combinations this calculator returns only one result and then we can be certain it is correct. However when two results are returned either one can be correct and about 1/3 of the time two results are returned. Be sure to scroll down far enough to see if there are two results.

Using the Calculator.net age and date calculator the following example illustrates the issue. Date of birth Feb 28 Date of death Apr 1 of same year Age at death using the calculator will be 1 month four days.

Now go to the date calculator at the same web site, use the “add or subtract from a date” section and enter the information:

Start date April 1 Enter 1 month four days Set it to subtract and click calculate The calculated birth date will be Feb 25. This website contradicts itself and no alternative date is given. I think the first calculator is better because it recognizes when there are two possible answers and gives both of them.