[UPHPU] Why do forums use Int(11) for dates?

[Brandon Stout]

Here's why I'm asking:

I'm migrating users from my main website to a new one more specific to 
their needs.  I use phpwebsite for mscis.org, but these users - people 
from my high school graduating class - just need a forum.  I've tried 
phpbb2 and Simple Machines (per earlier uphpu discussions).  I dumped 
the user names via phpmyadmin fine, but phpbb2 and Simple Machines both 
use an int(11) field for the CreateDate.  If it were a date field, I 
could just put in 20060406 for all of them, but I don't know how to read 
Int(11) dates... My 2 questions:

  1.  Why do people use Int(11) instead of Date fields?
  2.  What is today in Int(11) date format?

Thanks in advance.  I'll get back to the two php books I have from the 
last meeting to see if I find an answer there...
-- 

Brandon Stout
http://mscis.org