I'm confused about whether the Date class is built-in or in the
standard library.

I can use it without requiring it in irb, so that tells me it's built-in.
Pickaxe doesn't document it in the "Built-in Classes and Modules"
reference chapter.
Pickaxe does document a Date class in the "Standard Library" chapter.
Are there two different date classes?
Should I be able to determine this by looking at source files under
the lib/ruby/1.8 directory?
It's seems like those source files are all for standard library classes. True?

--
R. Mark Volkmann
Partner, Object Computing, Inc.