This is Perl module autobox::DateTime::Duration. INSTALLATION autobox::DateTime::Duration installation is straightforward. If your CPAN shell is set up, you should just be able to do % cpan autobox::DateTime::Duration Download it, unpack it, then build it as per the usual: % perl Makefile.PL % make && make test Then install it: % make install DOCUMENTATION autobox::DateTime::Duration documentation is available as in POD. So you can do: % perldoc autobox::DateTime::Duration to read the documentation online with your favorite pager. Tatsuhiko Miyagawa