time-to_f.rb

if Array.new(10) { Time.now.nsec % 1000 }.sum == 0
  puts "nsec precision not available"
  exit
end

a = 0
10_000_000.times do
  t = Time.now
  d = ( sprintf("%.9f", t.to_f).split('.')[1].to_i - t.nsec ).abs
  # edge case around 0 nsec where .to_f results in .999999999
  if d > 900_000_000
    d = (d - 1_000_000_000).abs
  end
  raise "bug" if d > 1_000
  a += d
end
puts a / 10_000_000.0  #=> 82.5188864, 82.4912323