function [year month] = set_yr_mon(date)

nt=length(date);

year = date/1e4;
month = (date-year*1e4)/1e2;

for n = 1:nt
  month(n) = month(n)-1;
  if( month(n) == 0 )
   month(n) = 12;
   year(n) = year(n)-1;
  end
end