I only started a few weeks ago, and I've been trying to post a few times a week: now, I just started a daily schedule, 'cause I want to get myself a little momentum and encourage myself into the habit of filming and working a little every day.
I do think that even just posting a few times a week, I've noticed that you gain more views back to back; what you need to remember is that not only is your video appearing new in the tags people are searching, when someone does watch a video of yours, they'll be recommended similar videos from you... If there are some to do so. The more videos you have, the more links people might be offered when watching your videos, et cetera. Building a back catalogue is still great over time, but when you do upload more often, that catalogue gets longer and longer.
Time of upload doesn't make as much of a difference as tagging your videos well, which is pretty crucial. Definitely get hold of a tool like TubeBuddy, or at least put the subject of your video into the search bar and see what the suggested results are to use as tags.