Why doesn't MMM DD, MMMM DD or M/DD work in custom formatting?

"Jack" wrote in message
oups.com...
I want to format a column ONLY using day and month so that I can sort
by that column. The default includes the year I have entered the data
(i.e. 2004 or 2005) which corrupts the sort. Anyway to remove it? I
have tried custom and special under format. Doesn't work. Thanks.

Jack