Category - put down what time of video it is, like gaming or music or comedy, something like that. So when people search your video has automatically been put into a category for it. It doesn't have much of an affect as tags or titles but it still does something. I would suggest if you post similar content across your channel, go into the advanced settings of your channel and switch it. That will apply it to all your vids not just the one you are uploading.
Video Location- this gives you the ability to target your audience. Youtube automatically does this by where you live,l say you live in Spain, it automatically makes the veiwers who have also signed up to living in spain see your videos more often. But with the video location, say you put down spain, but you normally live in Britain (vlog, vacation, just examples) this will show that specific video to spain more. I would suggest not over using it, because it could end up in a catastophe like last year where 50,000 people lost their channels because of tags abuse.
Recording date - It's very similar to upload date. when you search something on youtube, you have up at the top filters and one of the filters is like uploaded in last week, last hour, last month etc. Well this also puts a play into it. I believe that this works very similar, I don't know that much about this one. But when you upload a video and someone uses that filter, I think the recording date also helps decided where your video is put into the search list.
Hope this helped =)
