Python含时分秒倒计时开发求助：明日日期需显示0天

我是编程新手，借鉴他人代码进行优化，尝试用Python实现一款包含时、分、秒的倒计时功能。期望当输入的目标日期为明日时，程序能显示“0天”及对应的时、分、秒，但多次尝试均未成功实现该效果，同时也无法正常输出时、分、秒信息。以下是我编写的Python代码，希望获得思路指导而非直接完成代码：

from datetime import datetime
from datetime import date
import time

today = date.today()

def user_birthday():
    year = int(input('When is your birthday? [YY] '))
    month = int(input('When is your birthday? [MM] '))
    day = int(input('When is your birthday? [DD] '))

    birthday = datetime(year,month,day)
    return birthday

def hours_left(birthday):
    today == date.fromtimestamp(time.time() + 86400)
    birthday = date(today.year, birthday.month, birthday.day)
    if birthday == today.day + 86400:
      birthday = birthday.replace(day = 1 - 1)
      return birthday
    dt = datetime
    now = dt.now()
    hour = 24 - (now.hour + 1)
    minute = 60 - now.minute
    second = 60 - now.second
    hts = str(hour) + " Hours", str(minute) + " Minutes", str(second) + " Seconds"
    return hts

def calculate_dates(birthday):
    today == date.fromtimestamp(time.time())
    birthday = date(today.year, birthday.month, birthday.day)
    if birthday < today:
        birthday = birthday.replace(year=today.year + 1)
        return birthday
    elif birthday == today:
      birthday = birthday.replace(day = 1 - 1)
      return birthday
    elif birthday == today:
        print("Happy Birthday!")
    else:
        return birthday
 
bday = user_birthday()
t = calculate_dates(bday)
time_to_birthday = t-today
days = str(time_to_birthday.days)
day = time_to_birthday
htss = str(hours_left)
print("Days until Your Birthday : " + days + " days and" + htss)

核心思路调整方向 #

• 区分date和datetime类型：date仅包含年月日，datetime包含时分秒，倒计时需要精确到秒，全程使用datetime能避免类型转换错误，简化时间差计算。
• 修正赋值/比较运算符错误：代码中多处用==（比较）代替=（赋值），比如today == date.fromtimestamp(...)这类代码完全无法修改变量值，是无效操作。
• 重构日期比较逻辑：
  • 不要用today.day + 86400这种错误的比较方式，日期对象直接用</==/>对比即可。
  • calculate_dates里重复的elif birthday == today分支永远不会执行，需要合并逻辑。
• 正确计算时分秒：不要硬凑数值，应该通过目标datetime与当前datetime的时间差来计算剩余时分秒。比如用total_seconds = (target_datetime - now).total_seconds()，再把总秒数换算成小时、分钟、剩余秒数。
• 修正函数调用方式：htss = str(hours_left)是把函数本身转成字符串，正确做法是调用函数并传入参数，比如htss = hours_left(bday)，还要处理返回的元组（比如用' '.join(htss)转成字符串再拼接）。
• 实现0天逻辑：当时间差的总秒数小于86400秒（1天）时，就显示“0天”，再换算剩余的时分秒。

内容的提问来源于stack exchange，提问作者The.new.kid.on.the.block