Time synchronization keeps every device's clock aligned to a common reference, almost always using NTP (Network Time Protocol). In a surveillance system each camera, recorder, and server stamps its video and events with a time; if those clocks drift apart, the timestamps stop agreeing, and the whole system's account of "when" becomes unreliable. NTP, pointing all devices at the same time source, is what holds the timeline together.
Accurate, synchronized time is not a nicety — it is foundational to the evidentiary and investigative value of footage. Correlating an event across cameras (following a person from one view to the next), matching video to an access-control or point-of-sale record, and presenting footage as trustworthy evidence all depend on the clocks agreeing. A few seconds of drift can put two cameras' versions of the same moment out of step and undermine a reconstruction.
The pitfall is leaving time to chance. Cameras left on factory defaults, an unreachable NTP server, or time zone and daylight-saving mismatches quietly corrupt timestamps until the day an investigation needs them. Good practice is an explicit, monitored NTP hierarchy for all devices, with time zone handling agreed system-wide — and, for high-stakes evidence, awareness that defensible timekeeping may need a documented, traceable time source rather than a random internet server.
