Sort CB List by the MMDD component of a date field

I have tried several methods but am not getting closer to a solution, so I am tapping into the knowledge of the forum.

I have several lists where I want to ignore year when I sort a list by date. One is birthday where I want all of the birthdays ordered within a year, not by the year of birth. Another is a list of death dates where I want to order the list by the month and day and to ignore the year.

Any suggestions would be helpful. I can generate the required mmdd using a CB Query field, but these fields are not available for sorting.

Michael
Joomla 2.5.11
Apache 2.0.64
MYSQL 5.1.47
CB 1.9 loaded via quickstart pro 1.5

Query fields can't be used for sorting. Sorting uses the ORDER BY of the query on a _comprofiler column and query fields don't store to database so can't be sorted on. Only solution is to push the date-month to a new field (text field?) using CB Auto Actions maybe. Then sort by that new fields. Date fields always store with year, month, and day.