code: def get_day():
      
      day = datetime.datetime.today().weekday()
      if len(sys.argv) == 3:
          if sys.argv[2] == "mon":
              day = 0
          elif sys.argv[2] == "tue":
              day = 1
          elif sys.argv[2] == "wed":
              day = 2
          elif sys.argv[2] == "thur":
              day = 3
          elif sys.argv[2] == "fri":
              day = 4
          else:
              day = 5
      if day > 4:
          print("There is no information about the menu today.")
          exit(5)
      return day
docs: Function for retrieving the wanted day