old_contents: # birthday.py
  
  
  def print_header():
      """ Print the header for this app"""
      print("--------------------------------------")
      print("        BIRTHDAY COUNTDOWN APP")
      print("--------------------------------------")
  
  
  def get_user_bday():
      """ Get year, month and day as strings from user """
      year = input("Enter your year of birth(YYYY): ")
      month = input("Enter your month of birth(MM): ")
      day = input("Enter your day of birth(DD): ")
  
      # Strip the whitespaces and convert to integers
      year = int(year.strip())
      month = int(month.strip())
      day = int(day.strip())
  
      return year, month, day
  
  
  def calculate_days(bday):
      """ Calculate the number of days until the user's birthday """
      return 0
  
  
  def print_result(bday, days):
      """ Print the result to the user """
      print("Looks like you were born on {}/{}/{}".format(bday[0], bday[1], bday[2]))
      if days > 0:
          print("You celebrated your birthday {} days before".format(days))
      elif days < 0:
          print("You will celebrate your birthday in {} days".format(-days))
      else:
          print("Today is your birthday. Happy Birthday! Have a great one!")
  
      pass
  
  
  def main():
      print_header()
      bday = get_user_bday()
      days = calculate_days(bday)
      print_result(bday, days)
  
  if __name__ == '__main__':
      main()
  
new_contents: # birthday.py
  import datetime
  from collections import namedtuple
  
  Date = namedtuple('Date', ['year', 'month', 'day'])
  
  
  def print_header():
      """ Print the header for this app"""
      print("--------------------------------------")
      print("        BIRTHDAY COUNTDOWN APP")
      print("--------------------------------------")
  
  
  def get_user_bday():
      """ Get year, month and day as strings from user """
      year = input("Enter your year of birth(YYYY): ")
      month = input("Enter your month of birth(MM): ")
      day = input("Enter your day of birth(DD): ")
  
      # Strip the whitespaces and convert to integers
      year = int(year.strip())
      month = int(month.strip())
      day = int(day.strip())
  
      return Date(year, month, day)
  
  
  def calculate_days(bday):
      """ Calculate the number of days until the user's birthday """
      now = datetime.datetime.now()
      diff = now - datetime.datetime(now.year, bday.month, bday.day)
      days = int(diff.total_seconds() / 60 / 60 / 24)
  
      return days
  
  
  def print_result(bday, days):
      """ Print the result to the user """
      print("Looks like you were born on {}/{}/{}".format(bday[0], bday[1], bday[2]))
      if days > 0:
          print("You celebrated your birthday {} days before".format(days))
      elif days < 0:
          print("You will celebrate your birthday in {} days".format(-days))
      else:
          print("Today is your birthday. Happy Birthday! Have a great one!")
  
      pass
  
  
  def main():
      print_header()
      bday = get_user_bday()
      days = calculate_days(bday)
      print_result(bday, days)
  
  if __name__ == '__main__':
      main()
  
subject: Complete the app by adding the logic for calculating the days difference