def extra_hour_bits(value):
  """
  practice getting extra bits out of the hours bytes

  >>> extra_hour_bits(0x28)
  [0, 0, 1]

  >>> extra_hour_bits(0x8)
  [0, 0, 0]
  """
  masks = [ ( 0x80, 7), (0x40, 6), (0x20, 5), ]
  nibbles = [ ]
  for mask, shift in masks:
    nibbles.append( ( (value & mask) >> shift ) )
  return nibbles