The Double Rainbow Calendar is an idea thought of by Karl Palmen, which uses a six-colour rainbow twice: once for a six-day rainbow week and once for six seasons in a year.
Someone suggested a rainbow calendar the 7 rainbow seasons
I think six colours would be better (e.g. Violet, Blue, Green, Yellow, Orange, Red).
I've chosen the above for easy convertability to/from the Gregorian Calendar.
Also there is a rainbow week normally of six days, whose colours correspond to the seasons and occur in the same order (i.e. Violetday, Blueday, etc.). Each season begins on its own colour day (e.g. Yellow on Yellowday) So this forms a Double Rainbow Calendar.
In a common year the season of Blue has only 60 days instead of 61. The day that is skipped is day 30 (rather than 61). The corresponding day of the rainbow week (which is Violetday) is also skipped then. So Redday 29 Blue is always February 28 and Blueday 31 Blue is always March 1.
The six rainbow seasons are
|Violet||December 1 - January 30|
|Blue||January 31 - March 31|
|Green||April 1 - May 31|
|Yellow||June 1 - July 31|
|Orange||August 1 - September 30|
|Red||October 1 - November 30|
Each season has 61 days numbered 1 to 61, except the Blue Season in a common year, which skips day 30, which corresponds to February 29.
Example Dates: August 25 = Orangeday 25, Orange March 17 = Redday 47 Blue
There is also a rainbow week normally of six days whose days are named after the same colours as the seasons (Violetday, Blueday, Greenday, Yelllowday, Orangeday and Redday). Each rainbow season begins and ends on the same day of the rainbow week as its own colour (eg, Green season begins and ends on a Greenday). When the Blue season misses out Blue 30, it also misses out the corresponding day of the rainbow week (Violetday), so Blue 31 is always a Blueday (occurring on 1 March).