The primary differences between the 7-day rolling and the 30-day rolling storage are the price and the number of days that videos are stored in the cloud.
For example: if you purchase the 7-day rolling storage of a year VIP plan on January 1, 2019, and the Xiaomi Home Secure starts storing videos on January 1, 2019. On January 8, the system will automatically delete videos from 7 days prior (i.e., January 1 and start storing videos from January 2 to January 8. The deletion and storage process continues in this rolling manner, with videos being overwritten by the second).
You can choose a storage plan with a different number of days based on your actual needs. If you have important videos, you can download them to your phone in advance. (If the system is iOS, the system needs to be iOS 11.0 or above to purchase and use Xiaomi Home Secure properly.)