The YouTube page of a video displays only the date the video was published. However the YouTube API
provides a way to get the exact date+time of upload, as well as publishing.
The URL to use is this:
You've to substitute the video's ID into the videoid
field above. The XML returned by this API call contains a
field. But don't forget that these dates are in GMT (aka. UTC), so to get the times in your local timezone, you've to convert them appropriately.