my %out;
my %index;
my $precision = 10;
for my $val (@array)
{
  my $rounded = $precision*(int($val/$precision));
  die "Too many duplicates" if exists $index{$rounded} and $index{$rounded} == $precision;
  my $timestamp = $rounded + $index{$rounded}++;
  $out{$timestamp} = { One => 1, Two => 1 };
}

pp \%out;
__END__
{
  1000 => { One => 1, Two => 1 },
  1001 => { One => 1, Two => 1 },
  1002 => { One => 1, Two => 1 },
  1010 => { One => 1, Two => 1 },
  1011 => { One => 1, Two => 1 },
  1012 => { One => 1, Two => 1 },
  1020 => { One => 1, Two => 1 },
  1021 => { One => 1, Two => 1 },
  1022 => { One => 1, Two => 1 },
}