Do You Follow A Upload Schedule?

To answer your question about whether to upload a video early prior to the scheduled dates you told your viewers no I wouldn't do that. But if you miss a day and then want to upload a video on a random day that's fine. I know it kind of contradicts itself but you want to try your best to follow the same pace.

As for me having a schedule.....I'm not too strict on myself that i HAVE to make a video every week otherwise then it wouldn't be fun for me. However, when it's christmas or halloween that's the only time I follow a schedule and make sure I post a video each sunday.
I use to upload every Thursday, but my school schedule made it difficult. Now I upload every Sunday.

I haven't missed a post day yet either! Having a deadline helps push me
At one point, it was a video a week, but that was when I was operating on my iPhone and was very limited in what I could do. Now I have a better camera and bigger ideas, there can be a couple of weeks between videos. But that's the longest it's ever been. I don't like them being that few and far between - my language videos are a lot easier to shoot and edit, whereas my photography videos now take a little time to put together - but I hope that as I get into the swing of things, I'll be able to upload more frequently.
I've been hiatus since May, working on rebooting my entire Channel and such. But, when I'm finally finished, I plan to have a schedule of a Sunday release every week. Since my videos take so long to edit though, I have no idea if that will work, though.
I think that having an upload schedule, especially today on YouTube, is essential in being successful. Just think about it, most YouTubers get bigger and bigger by posting cooler, better, funnier videos. Making content like that takes practice and uploading on and especially sticking to that schedule will increase your chances of getting YOUR content out there. I do understand though sometimes you just can't get a video out because of personal issues or even just from being lazy and forgetting. It happens lol
I try to upload two videos per week at least, one around Wednesday and other on Sunday. Since I onl have one computer and I use it for work and college and everything, basically, sometimes I cannot leave it reenderizing a video until I am done with everything else so it makes things tough. So my schedule it's two per week, and I hope one day I can have a fixed schedule so people will know when to look for my new content.
same here I try my best to upload twice a week
Personally I feel it is important to stand by your word the best you can. So in your case I would try to air every Friday as you told your viewers. It can be tough to uphold a schedule. However it is helpful if you record a few videos in advanced, so that you don't fall behind. If you get sick or something else happens you have content to release for a few weeks.

I personally recorded a month worth of videos in advance, giving myself plenty of time for creation and editing. I release 4 videos a week at minimum, and many times its 5 videos. For example in my case I follow the schedule below.

Mondays: Proof Requests (4pm CST Weekly)
Tuesdays: Etymological Love (4pm CST Bi-Weekly)
Wednesdays: Arcanum Random Thoughts (4pm CST Occasionally)
Thursdays: Arcanum Luminarium (4pm CST Weekly)
Fridays: Questions & Answers (4pm CST Occasionally)
Saturdays: Arcanum Trew News (4pm CST Bi-Weekly)
Sundays: Father Arcanum (11am CST Weekly)

Hope this helped you out, just my opinion but works for me.
Damn strait. My audience is the 65+ crowd so when they are used to Matlock at 5:00 PM every Wednesday you damn well better guarantee the same security with your channel.