Selecting one MySQL date with month reduced by one I was thinking in a way to improve the following query if possible:

SELECT CONCAT(DATE_FORMAT(start_date, '%Y'), ',', 
       (MONTH(start_date) -1), ',', DATE_FORMAT(start_date, '%d')) as start_date
FROM PROJECTS


I need start_date in this format: dd/mm-1/yyyy.

Note: I am using an API that use month from 0 to 11, and MySQL uses 1 to 12 &ndash; that's why I need month - 1.
If there is no workaround then, bad practice as it may be, what you have is functional. I found this post on SO that may allow you to convert the column's date data type to the 0-11 format. Hope this helps. 

EDIT

Removed bad idea. If you really wish to see it just look at the edit history, but it is not a good idea. I'm going back to my original answer.