An inaccurate clock looks trivial until footage is needed as evidence, where a scrambled timeline can break the chain of proof.

1. Enable NTP: configure a time server on both cameras and recorders and schedule a daily sync so the clock cannot drift over months.
2. Check time zone and daylight saving: a wrong zone shifts everything by whole hours, and an unhandled DST rule introduces a one-hour jump twice a year.
3. Check the coin cell: many devices rely on a small battery to hold the clock. Once it dies, every power cycle resets the time to factory default.
4. Single time source: devices syncing to different servers disagree with each other. Have the recorder push time to the cameras so the whole site shares one reference.

Operationally, sample the drift weekly and cross-check against the recorder operation log so that timestamps, channels and actions corroborate one another.