docs: def months_ago(date, nb_months=1):
      """
      Return the given `date` with `nb_months` substracted from it.
      """
      nb_years = nb_months // 12
      nb_months = nb_months % 12
  
      month_diff = date.month - nb_months
  
      if month_diff > 0:
          new_month = month_diff
      else:
          new_month = 12 + month_diff
          nb_years += 1
  
      return date.replace(day=1, month=new_month, year=date.year - nb_years)