How long does the video surveillance of five-star hotels in Ningbo last?

Generally, a hotel monitoring system like Shennai 'an in Shenzhen requires that the video be saved for one month, but the exact time depends on the size of the hard disk used in practice. The larger the hard disk, the longer it will be stored? Is it usually about a month? If you know the size of his hard drive, you can do the math yourself. I'll give you a conversion formula, and you can calculate it.