How to Add an Accurate Time-Stamp to Surveillance Video

Why the time-stamp matters

Your report says the Subject carried a bag of mulch to the truck at 8:05 A.M.; the video should show 8:05 A.M. at that moment. When the time on the video doesn't match the report, the difference becomes a question on cross-examination, even if the observation itself is accurate.

A time-stamp drawn on the picture also lets an adjuster or attorney find a moment quickly and tie it to your narrative without opening file properties.

Where a video's time comes from, and how it goes wrong

• Phones write the recording start time into the file, usually correct and with the time zone
• Many cameras write a creation time in UTC, which looks hours off until it's converted
• Some files only carry the time they were saved, which is often when the recording ended, not when it began
• Dedicated cameras and DVRs use their own clock: never set, drifted by minutes, or not changed for daylight saving
• Copying files can change the date a computer shows for them, so never rely on what the file browser says

Step by step

1. Copy the original files off the camera or phone and keep them unchanged. Record a SHA-256 fingerprint of each so you can show later that they weren't altered.
2. Find when each recording started, and note where that time came from (the phone, the file's creation time, or the camera's clock).
3. Check each camera's clock against a reference: a phone or GPS clock in frame, a clock on a building, or an event you logged in your field notes with its time.
4. Correct the whole camera by the same amount, unless you have a reason to correct clips differently.
5. When several cameras covered the same day, line them up by time: one camera's clip starts where the other's ends.
6. Burn the corrected time into an exported copy, second by second, in the same 12-hour format your report uses.
7. Document the correction: the time in the file, the corrected time, how you determined it, who made the change and when.

Example correction note

V002 (camA2.mp4), Sony FDR-AX43
Time in the file:   10/30/2026 8:05:00 A.M.
Corrected start:    10/30/2026 8:06:00 A.M. (1 min later)
Basis:              At 0:38 into the clip, the Investigator's phone clock,
                    visible in frame, read 8:06:38 A.M.
Changed by:         Investigator, 11/01/2026 10:44 A.M.

Doing it in PIwitness

PIwitness's video editor follows these steps. Uploads are fingerprinted, and each video shows the time read from the file and where it came from. Pause on a frame where you know the real time and type it to correct one clip or the whole camera; line up a second camera by where the first one ends. The export burns in the corrected time exactly as the editor shows it, and the Project Action Report records the time in the file, the corrected time, how far it moved, and who changed it.

Frequently asked questions