Thread:Project:Support desk/Redirecting categories

I have searched without success for a definitive answer. Is it possible to merge two categories by using a redirect?

For example, I have articles in Category:March 10 and some in Category:10 March. I thought that redirecting Category:March 10 to Category:10 March would make the articles appear under 10 March. My attempts have so far failed. Is there a method or is it a case of fixing all the incorrect articles?