It really is very disappointing that after 3 versions, and 110 bug fixes, basic things like importing or managing a video file by date is still completely broken.
Even more troubling, is that for someone who uses LR3 this is a very obvious problem, and should be very easy to fix.
When you import a file on a wide range of cameras the date that is used for the video file as far as LR3 is concerned is the date you are importing it, not the date it was taken. This makes any management of the file, especially when managed next to pictures, very difficult.
The problem, as far as I can tell, is that in Windows, a file has both a 'Date Created' and a 'Date Modified'. 'Date Created' is whenever the file was created on the PC. If you bought a new computer and transferred a bunch of files over on 30/12/2010, all of your files will have a 'Date Created' that is 30/12/2010 regardless of when the photos or videos were taken. Or if you take a video on September 1st and import it onto your computer September 15th, it will have a 'Date Created' of September 15th.
'Date Modified' however lists the date that the file was last changed. For video files, that most likely was the date the video was shot.
Every program I have ever used for video files has always organized them by Date Modified (when organizing them by date). For example, its the default in Windows 7 Explorer when showing video files, all the video files listed by the date you have taken them. Date Created really doesnt have any useful information.
Its inexplicable to me why LR3 uses Date Created instead of Date Modified. It is a glaring error, that should be easily fixed. Microsoft can manage to do it right, as a byproduct in its OS, Im not sure why an imaging company in a $400 piece of specialist software cannot.
And just in case this is overlooked as a minor problem, it certainly is not. It happens to the following cameras:
D90 (first camera to shoot video)
D3s (thought by many to be the best low light camera)
D7000 (likely to be Nikon's most important DSLR)
D3100 (likely to be Nikon's most purchased DSLR)
Canon S95 (one of 2 most popular P+S for DSLR owners)
Fuji 31fd (Ill never forget you!)
And those are just the cameras I have on my desk, Im sure it happens to many others.
Also, when importing these files by date, LR3 will import them into a folder 1 date later then the date that LR3 is using for the file. So, just to be clear, you could take a video on May 1st, import it into LR3 on May 2nd and LR3 would say it was taken May 2nd, and it would be placed in the folder for May 3rd.
Im really not sure why something so basic has not been addressed in so long, and it makes any sort of managment of video files by date in LR3 useless.
I agree that the wrong file system date is being used. But I scanned all my Lightroom files (manually) tagged with 'video'. When the file contains suitable metadata with a capture time that is used. When that's missing, the (wrong) file system date is used.
Interestingly I even found one camera where the dates were originally right (in 2009), then disappeared for a while (probably due to a firmware upgrade!) and then came back again. Summary of what I found:
Very old (Philips) webcam / format AVI / no metadata visible / wrong date
Canon Powershot A80 / format AVI / metadata visible / right date
Nokia N73 cellphone / format MP4 / no metadata / wrong date
Canon EOS 5D Mark II around 2009 / format MOV / metadata visible / right date
Canon EOS 5D Mark II around 2010 / format MOV / no metadata / wrong date
Canon EOS 5D Mark II around 2011 / format MOV / metadata visible / right date
So my conclusion is that the camera makers are making a bit of a mess when they introduced video. Nikon introduced its video a year or so later than Canon. I don't know if "no metadata" means that there is none, or that Adobe just doesn't like the format. But given the pattern of the firmware updates with Canon, it looks like Canon and Adobe ultimately agreed on the format. But in any case Lightroom (I am using 3.4.1) has a bug w.r.t. its fallback scenario of reading file system dates.
In my case, the dates changed when I copied all my data from one disk (old NAS) to a new one (new NAS). It is disconcerting that you get the copying date despite comparison tools declaring the files to be identical (Beyond Compare 3 also keeps an eye on date differences).
Hope this helps, Peter