Update: I thought I was in a different thread so much of this is incorrect. My apologies to slayven. ):

Note that this does d-m-yyyy which isn't what was asked for (the order is wrong and you don't pad with zeros).

use mapcar;
print join '-', mapcar {sprintf "%02d",pop()+pop}
    [(localtime())[5,4,3]],[1900,1,0];
[download]

Is my contribution (which does yyyy-mm-dd since that is simply a better format).

See mapcar -- map for more than one list for one needed part.

        - tye (but my friends call me "Tye")