[RESOLVED] Age Calculation

[dbasnett]

Lets say you are born on 1/1/2000 @ 12:00:01 AM. You are one day old correct?

On 1/2/2000 you are 2 days old.

On 1/8/2000 you are 1 week old.

On 1/15/2000 you are 2 weeks old.

On 12/31/2000 you are 366 days old. (leap year)

Therefore, on 1/1/2001 aren't you 1 year and 1 day old?

I ask because I have an issue with an age calculator that I wrote.

[wy125]

Hi DBasnett,

I think you meant 1/1/2001 on the last line of your post. I think you're right. At least as far as we casually consider our ages. I suppose you could calculate the number of days that have elapsed from birth to current and then divide by 365.24 (and how many other decimal places that I don't know) to figure out a more precise age. I guess it depends on how you want to look at what a year is.

[dbasnett]

thanks for the catch, i fixed it in the original. i am still working on it, trying to have it both ways without creating a huge kludge. it works great, including leap years, for everything but the anniversary date (birth date).

[wy125]

what's the problem with the anniversary date?

[dbasnett]

anniversary is a date in the past, like birthday. here are my results:

birthday = 1/1/2000 - 2000 is leap year

On 1/1/2000 - 0 days old
On 1/2/2000 - 2 days old
On 1/8/2000 - 8 days old
On 12/31/2000 - 366 days old
On 1/1/2001 - 1 year 0 days old
On 1/2/2001 - 1 year 2 days old
On 12/31/2001 - 1 year 365 days old

[wy125]

hmm... I just thought of something. I think it would make sense to define a year with a fractional number of days (365.24...) and just divide the number of days by that number to get their age.

The reason I think you should go that way is, what happens if say someone is born March 1 in a leap year. After how many days would they be considered 1 year old according to the calculator?


Edit: Shouldn't a year be the same number of days even if it is a leap year? a leap year just adds an extra day before we can change the calendar year, it doesn't add another day to an actual year.

[szlamany]

Lets say you are born on 1/1/2000 @ 12:00:01 AM. You are one day old correct?

I kind of take issue with this statement.

Are you saying that at one second into your life you are one day old?

[dbasnett]

format of output

birthday asOfDate age

method1
1/1/2000 1/1/2000 yrs = 0 days = 1
1/1/2000 1/2/2000 yrs = 0 days = 2
1/1/2000 12/31/2000 yrs = 0 days = 366
1/1/2000 1/1/2001 yrs = 1 days = 1
1/1/2000 1/2/2001 yrs = 1 days = 2
1/1/2000 12/31/2001 yrs = 1 days = 365
1/1/2000 1/1/2002 yrs = 2 days = 1
1/1/2000 12/31/2004 yrs = 4 days = 366
2/29/2000 3/1/2001 yrs = 1 days = 1
2/29/2000 2/28/2003 yrs = 2 days = 365
2/29/2000 3/1/2003 yrs = 3 days = 1
2/29/2000 3/1/2004 yrs = 4 days = 2


method 2
1/1/2000 1/1/2000 yrs = 0 days = 0
1/1/2000 1/2/2000 yrs = 0 days = 2
1/1/2000 12/31/2000 yrs = 0 days = 366
1/1/2000 1/1/2001 yrs = 1 days = 0
1/1/2000 1/2/2001 yrs = 1 days = 2
1/1/2000 12/31/2001 yrs = 1 days = 365
1/1/2000 1/1/2002 yrs = 2 days = 0
1/1/2000 12/31/2004 yrs = 4 days = 366
2/29/2000 3/1/2001 yrs = 1 days = 0
2/29/2000 2/28/2003 yrs = 2 days = 365
2/29/2000 3/1/2003 yrs = 3 days = 0
2/29/2000 3/1/2004 yrs = 4 days = 2

[dbasnett]

i think this is the correct answer

2000 and 2004 are leap years
1/1/2000 1/1/2000 yrs = 0 days = 0
1/1/2000 1/2/2000 yrs = 0 days = 1
1/1/2000 12/31/2000 yrs = 0 days = 365
1/1/2000 1/1/2001 yrs = 1 days = 0
1/1/2000 1/2/2001 yrs = 1 days = 1
1/1/2000 12/31/2001 yrs = 1 days = 364
1/1/2000 1/1/2002 yrs = 2 days = 0
1/1/2000 12/31/2004 yrs = 4 days = 365
2/29/2000 3/1/2001 yrs = 1 days = 0
2/29/2000 2/28/2003 yrs = 2 days = 364
2/29/2000 3/1/2003 yrs = 3 days = 0
2/29/2000 2/29/2004 yrs = 4 days = 0
2/29/2000 3/1/2004 yrs = 4 days = 1

[dbasnett]

final test

2/29/1008   3/1/2009   yrs = 1001     days = 0

[dbasnett]

thanks for helping everyone. i had been thinking about this since early yesterday afternoon. it is funny how something so simple can get hard if you think about it too much.

2/29/1008    2/28/2009    yrs = 1000    days = 365

[mendhak]

You are one day old on the second day, because the first day has completed. It's similar to you being one year old after the completion of a year.