PhotoEntry.setTimestamp ignored for videos

[httpdispatch]

That is not possible to update video or video exif timestamp using the API. I've tried

PhotoEntry.setTimestamp()
PhotoEntry.setTimestampExt()
PhotoEntry.getExifTags().setTime()

After the PhotoEntry.update() method is called the updated data are sent to the server (i can see that in the log). But server ignores the updated values.

I can see the same issue in the Picasa Desktop software. I can modify video time there but in the server it will not be updated.

However it is possible to update video timestamp using photos.google.com web site.