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I have an interesting problem. I want to compute a birthdate (Month Date, Year) from a given age. I understand that subtracting the given age from the current date will supply the year of birth, but what about the month and date? Any thoughts are welcome.

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I don't think you can find birth month and day from someone saying "I'm 62 years old!" – MITjanitor Jan 25 '13 at 21:56
This is definitely not calculus. – Thomas Andrews Jan 25 '13 at 22:05
You can't even get year. You can only get year within 1. For example, I am the same age now whether I was born Jan 1, 1977 or Dec 31, 1976 – Thomas Andrews Jan 25 '13 at 22:07

You cannot calculate the month and day without some information about the portion less than a year. Would you be given the age as 84 years and 256 days old? If it is, it probably should be calculated in excel or something easy like that. The cell reference would be =(NOW()-A1*365-A2) formatted as a date. Place the number of years in A1 and number of days in A2. I used excel only because almost everyone has it.

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Actually figured it out. Since I have the units (for ex. hours) just convert the age given with the units hours (for ex.) into days and subtract the number of days from the current or reference date and you have an approximate birthdate from the age. – user59682 Jan 28 '13 at 18:56
yes. that would work. that is the same way the equation above works. Generally, you would not have the units and say that you have someone's age but if you do, that is trivial. – kaine Jan 28 '13 at 22:49

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