my $start_date = "2005-07-12";
  my $end_date = "2005-08-03";

  use Date::Calc qw/Delta_Days Add_Delta_Days check_date/;
  my @start_date = split /-/, $start_date;
  my @end_date = split /-/, $end_date;
  die "Bad start date" unless check_date(@start_date);
  die "Bad end date" unless check_date(@end_date);
  die "bad order" unless Delta_Days(@start_date, @end_date) >= 0;
  my @d = @start_date;
  while( Delta_Days(@d, @end_date) >= 0 ){
    printf "%04d-%02d-%02d\n", @d;
    @d = Add_Delta_Days(@d, 1);
  }