So I have to mention a cool little thing I found on-line at the website www.timeanddate.com/date/
This website has calculators that can come in hand when trying to calculate ages of people from older headstones. Say your headstone says something like “Died April 13, 1812 Aged 45 Years, 3 Months and 2 days” You go into their “Date calculator: Add to or subtract from a date” and enter in the death date and then subtract the amount of years, months and days and it calculates that that person would have been born on or about Sunday, January 11, 1767. Yes you could have figured it out on your own but I don’t know about you but it would have taken me a bit to do the math.
They also have a calculator that will give you the amount of time between two different dates. You could use it to figure out exactly how old someone was when they died down month and days or use it to calculate any number of other events. I actually calculated how old I was and celebrated my 15,000 birthday last fall. 15,000 days that is. So much more exciting than 41.