[Python] Website monitor script stops working after a few hours?

This is the script with sensitive information redacted. After a few hours, the python window is still open but it stops updating. The website updates but the script doesn't catch it. It immediately sees the update if I close and re-open the script.

import time
import os
import yagmail
import datetime
import subprocess
import subprocess, os, platform

import requests
from bs4 import BeautifulSoup
import re
from datetime import date

monitoring_interval = 60

today = date.today().day
updated_time = ""

while today != updated_time:
page = requests.get(URL)
soup = BeautifulSoup(page.content, "html.parser")

updated_time = soup.findAll('div', class_=['left'])
updated_time = [res.text for res in updated_time]
updated_time = re.search(r"(?<=Last updated ).+(?=\n)", updated_time[0]).group()
updated_time = datetime.datetime.strptime(updated_time, '%H:%M:%S %Y-%m-%d')
updated_time = updated_time.day

print("Change detected")

time.sleep(999999)

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