Create a program which greets me every morning and calculates how many days I still have to live until I am at the average age of 85 years old. My birthday is on 10.1.1980.

def days_left(birthday):
    current_date = datetime.datetime.now()
    next_birthday_date = datetime.datetime(current_date.year, birthday.month, birthday.day)
    if next_birthday_date < current_date:
        next_birthday_date = datetime.datetime(current_date.year + 1, birthday.month, birthday.day)
    return (next_birthday_date - current_date).days

def days_left_to_85(birthday):
    current_date = datetime.datetime.now()
    return (datetime.datetime(current_date.year + 85, birthday.month, birthday.day) - current_date).days

def main():
    birthday = datetime.datetime(1980, 1, 10)
    if days_left(birthday) == 1:
        print("Hey, it's your birthday today!")
    else:
        print("Hey, your birthday is in {} days!".format(days_left(birthday)))
    print