$ date +%Eg
%Eg
$ date + %Eg    

$ date + %C 

$ date +%C 
Tue Aug 20 16:46:32 EDT 2002
$ date +%Og
%Og
$ perl -MPOSIX -e 'print strftime("%Og",localtime()),"\n";'
%Og
$ perl -MPOSIX -e 'print strftime("%Eg",localtime()),"\n";'
%Eg
$ perl -MPOSIX -e 'print strftime("%Eg",localtime()),"\n";'
%Eg