day_code in matlab package

[feroda]

In the recently released matlab package, there is some lines in /utility/date_stamp.m saying:
%---------------------------------------------------------------------------
% Get day of the week code.
%---------------------------------------------------------------------------

iwday = day_code(imonth,day,year);

So, what is the function of day_code? I can't find it(day_code.m) anywhere in the package.

Thanks

[kate]

See attached.