formatDuration behaves unexpectedly and ignores part of the input

[mihaisavezi]

There is definetely something wrong, or at least unexpected

// received
formatDuration(
  {
    years: 2,
    months: 9,
    weeks: 1,
    days: 7,
    hours: 5,
    minutes: 9,
    seconds: 30
  },
  { format: ['months', 'weeks'] }
) === '9 months 1 week'
// expected --> 24 + 9 months = 31 months 1 week

what I'm asking the function is to get my duration input and format it in months and weeks, not completely exclude part of the input, correct ?