To maintain the time and date the protocol ntp is used. This protocol is the one that is used to maintain most computers system time.
When the device boots up, it starts checking it’s time each three minutes connecting to the Internet time servers. If the connection to Internet is lost, the system will maintain the time correctly, and when the connection is recovered it will keep on ensuring that is on time each three minutes.
If the system is rebooted and the Internet connection is lost, it will not be able to adjust it’s time until the connection is recovered.
