WorkWeek:
  0: {day: 1, length: 0}
  1: {day: 2, length: 0}
  2: {day: 3, length: 8}
  3: {day: 4, length: 0}
  4: {day: 5, length: 0}
  5: {day: 6, length: 4}
  6: {day: 7, length: 8}