The Rainbow Alphabet Calendar is a calendar reform concept created by Karl Palmen. It has 52 rainbow weeks named after the letters of the alphabet 'A' to 'Z' and 'a' to 'z'. The days of the rainbow week are Redday, Orangeday, Yellowday, Greenday, Blueday, Indigoday and Violetday. Week 'Z' also has a Magentaday and so does week 'z' in Rainbow leap years. The Magentadays ensure that there are exactly 52 rainbow weeks in a year. They cause the rainbow week to move relative to the 7 day week. Reddays occur Rainbow Alphabet Years 2006 to 2010 as follows: