2003-09-25 IKEBE Tomohiro <ikebe@edge.co.jp>

• added Date::Simple MixIn interface. (Tatsuhiko Miyagawa)
• modified equinox algorithm (based on Ruby's holiday.rb)

2003-09-16 IKEBE Tomohiro <ikebe@edge.co.jp>

• Date::Japanese::Holiday is-a Date::Simple.
• includes Sunday, substitute holiday and special holiday.
• some internal method names are changed.
• added functional interface.

2002-12-05 IKEBE Tomohiro <ikebe@edge.co.jp>

• 0.01 original version
• 0.02 fixed Happy Monday calculation.