Date algorithms

[Eliot Finley]

This may not be the right place to ask this, but I saw the algorithms that 
I need posted here a while ago.  I'll be writing them in C, but I could
use them in any form.

Given the year, month, and day of month, I need to determine the day of the 
week...  I also need to convert dates to Julian numbers and back.

If anyone has the above info, it would greatly be appreciated.

           Please email to efinley at peruvian.utah.edu

If I get a mail box full of me-too's then I'll post.