Tombstone Challenge: Can you tell me the Birthdate?

Question

Tombstone says:

Died: 28 Aug 1858

Age: 33 Years, 8 Months, 28 days

(Yes I have used the online calculators)

Can you tell me the CORRECT birthdate?

Bonus points if you explain your answer.

Answer 1

Using the 8870 "rule":

18580828-00330828=18250000-8870=18241130

Comments

What is the 8870 rule?

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"8870"

Gravestones often supply only the Date of Death and Age.
A swift way to calculate the date of birth is as follows:

Suppose a person died May 6, 1889 at the age of 71 years, 7 months and 9 days:

1. Write the Death date year, month, day as............. 18890506

2. Subtract the age at death.......................................... 710709

3. This gives the figure ............................................ 18179797

4. Now subtract 8870 ....................................................8870

5. The result is .......................................................18170927

Which reads as year 1817, 9th month (September), 27th day

http://www.onhgs.org/bdatecalc.htm

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That's actually pretty cool.

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Now that is cool!  All the online tombstone calculators were giving me the 31 Nov 1824.

I did go with 30 Nov after some calculating of my own.  

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The 8870 formula isn't 100% accurate 100% of the time, and there are a few 'tricks' to using it properly, but it is quick, most often right, and out only a little when it is wrong. Also since it was often used for determining the age that was put on grave stones it will sometimes be more accurate on DOB than the precise calendar calculation.

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You are one of the genies at WikiTree!

Tell me, please, when is it wrong; does it have anything to do with the Gregorian calendar?

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I always just calculate when their next birthday would be.

Answer 2

Is it November 30, 1824?

28 days is December 28, 1824.

8 months would be August 28, 1825

33 years would be 1858.

Answer 3

Yes November 30 1824

28 days = July 31

8 months = November

33 years = 1824