如何通过Youtube API获取视频上传日期？

I'm confused as to where I can find the date a youtube video was uploaded. I've been using the following two functions:

$videoEntry->getUpdated()->getText();
$videoEntry->getVideoRecorded()

The first is when the video was last updated, and I'm not so sure that is the same as when it was uploaded. The "video recorded" is not always present. I assume its taken from camera metadata.

I need the date it was uploaded to the youtube website. Thanks.

I was actually hoping for an answer through the PHP API specifically. None of the functions in the documentation were working, though I was able to get the date uploaded from PHP like so:

$videoEntry->mediaGroup->uploaded->text

From the YouTube API Reference Guide.

"The <yt:uploaded> tag specifies the time that a playlist entry was originally uploaded to YouTube."

If you just browse the feed file for a particular video, such as http://gdata.youtube.com/feeds/api/videos/bTL5bErRk-g, you can see the uploaded date in the "published" tag, near the top:

<entry>
    <id>http://gdata.youtube.com/feeds/api/videos/bTL5bErRk-g</id>
    <published>2009-08-02T13:59:54.000Z</published>
    <updated>2009-10-29T11:20:11.000Z</updated>
...

Whatever 'published' technically means to YouTube, that's my video, and I can confirm that that's when I uploaded it.

For Youtube V3, it's something like this:

https://www.googleapis.com/youtube/v3/videos?part=snippet&id=(youtube_video_id)&key=(your_oauth_key)

"publishedAt" seems to have the date and time of publication in UTC timezone