Time is a critical resource for any game, but especially MMOs. In HeroEngine, the game clock on all clients is automatically synchronized with the area server they are attached too. Area server clocks are synchronized via. system time sync mechanisms.
Since each client (a user's PC) has its own clock which can be set to any time, and can run at fast or slow (almost always one or the other) then there needs to be a way for the Area server processes and the attached clients to agree on what time it is. This is done through time synchronizing. For example, if the client's clock is running a bit faster than the server, then eventually in an attempt to get back in synch, the client will either run a bit slower, or even stop, in order to resynchronize with server time (note: time will never move backwards).
This process happens automatically and does not require any input from your developers.