From: "Paparodopoulos, Nikos" <NPaparodopoulos@ing.gr> Sent: Feb 7, 2005 3:59 AM

> I have a data file that includes Individuals of which ID , BIRTH_DATE , > DEATH_DATE are given.

> I would like to calculate the individual exposure for various time periods > (i.e. time periods are taken to be years from 1995 to 2004, exposure is the > portion of the period in which the individual is alive).

I'm traveling; away from my mail archives, references, and SPSS.

But this is analogous to calculating the number of days of hospitalization for a patient by calendar month. Both Jan Spousta and I have posted solutions to that, though I regret I can't point you to exact subject lines and dates. I believe that Jan's solution, which I think the most efficient and elegant that's been posted, would solve your problem nicely.