I have heard a lot of misunderstood statements about time/date stamps on videos. The one that makes me scratch my head the most is For Court we must display the time and date in the video. I really do not understand that one. The reason I say this is that nearly all HD recorders now used by both law enforcement and professional investigators do not put a time/date stamp on the video. That means for court someone would have to provide a video that was not how it was recorded originally. No matter how you want to word this - it means you are providing an altered or modified video.
I have problems with getting altered videos into court. You are just asking for a good attorney to muddy up the water of your testimony. Usually to get video into evidence, whoever shot the video will be asked "Is this video the same as the actual scene when you shot it?" Fair enough, and easy yes. Then they need to ask "Have you modified, changed, or edited this video in any way?" If you answer any other way than "yes" you have just committed perjury if you used one of the common ways to add time/date stamps to the video. The most common is for people use the video out and play the video with the camera showing the time/date stamp and making a DVD on a Pinnacle Dazzle (or other brands that do the same thing) DVD recorder. That is no less a modified video that if you used a software program to edit the video so it shows the time/date based upon the meta data.
On a HD video the information is all contained in the file's meta data. This means you can look at the file and see when it was recorded. It has other information, such as the quality of the recording, etc.
The point is, you need to save an original recording how is was saved by the camera. It is not necessary to save SD cards, you just need to save the files in their original form and keep copies in a safe place.
You need to have that original form available when you go to court. You can say how you got the time/date stamp onto the video - but never claim that said video is original.
Whatever you do - stay safe!