import datetime

now = datetime.datetime.now()
print('当前时间:', now)
print('小时:', now.hour)

if now.hour < 16:
    yesterday = now - datetime.timedelta(days=1)
    check_date = yesterday.strftime('%Y%m%d')
    print('检查日期:', check_date)
else:
    check_date = now.strftime('%Y%m%d')
    print('检查日期:', check_date)