Your home's Wi-Fi allows you to check your internet time, but if you connect to someone else's Wi-Fi, this information may not be accessed. In some cases, if you access the Internet through the Internet through the gateway and have access control lists (ACLs) turned on, the gateway may record the time spent online. However, this information was usually only stored in the gateway and not on the network. If you are connected to public Wi-Fi, this information may be accessed by third parties but will only be recorded under certain circumstances. It should be noted that even if the access control list is turned off, this information may be leaked for some reason. Therefore, in order to protect the security of the online time record, it is recommended not to open any access rights when using public Wi-Fi and to back up the data regularly.