from datetime import *

format = "%Y-%m-%d %H:%M:%S"

a=datetime.now()

day=a.day

b=a.replace(day=day+1)

s=b.strftime(format)#datetime类型转化成 string类型

expire_time=datetime.strptime(s, format)#string类型转化成datetime类型

now = datetime.now()

if now<expire_time:

    return True