new_contents: from datetime import timedelta, datetime
  
  __EPOCH = datetime(day=5,month=1,year=1970)
  
  def __date_to_datetime(date):
      return datetime(date.year, date.month, date.day)
  
  def weeks_since_epoch(date):
      days_since_epoch = (__date_to_datetime(date) - __EPOCH).days
      return days_since_epoch // 7
  
  def weekday_ranks(date):
      '''Returns n so that if date occurs on a certain weekday, this is the
      n-th weekday of the month counting from 0. Also return 4 if this the
      last suck weekday of the month. '''
      n = 0
      month = date.month
      i = date - timedelta(days=7)
      while i.month == month:
          n += 1
          i = i - timedelta(days=7)
      if (date+timedelta(days=7)).month != month and n != 4:
          return n, 4
      else:
          return n,
  
subject: add new module with random utility functions