date-fns: Convert duration months to days

index.ts

import { intervalToDuration, isAfter, eachDayOfInterval, addMonths } from 'date-fns'    

const remaining = intervalToDuration({
  start: now,
  end: target
})

const days =
  remaining.months && remaining.days
    ? remaining.days +
      eachDayOfInterval({
        start: now,
        end: addMonths(now, remaining.months)
      }).length
    : remaining.days