For modern telecommunication devices a second is a very long time and during such a time many things may happen. In the same time, devices connected one to another through the net should always reliably recognize what happened earlier and what appeared later, which message is a question and which is an answer. And therefore it is so important to have the same nominal time at all the network points. It should be noticed, that in navigation systems the time is a primary factor of calculated position accuracy and is defined as exactly, as possible.
Ntp protocol is a standard protocol used in the Internet for time synchronization.
It uses a 32-bit counter for counting seconds, beginning from the year 1900.