In most places on the forum it's 72 hours, aka 3 days and only where it makes sense to bump. The exception of a single day is really for people who are adding new content to their resource sharing threads and isn't a hard and fast exception, more of a "if it makes sense and you aren't spamming we'll allow it". I merged the posts but I'm not certain about whether or not the exception should apply here. Usually it's not a problem so we've never had to make that decision. I'm leaning towards a no.
Personally I haven't been responding to your newer pieces because they all have the same problems I pointed out in the first one, and you never answered my questions about that one that would help me tell you the best solution for getting rid of those problems. If you're happy with the way things are with the things I pointed out I don't really have anything useful to add. You shouldn't probably put all of your monsters up here for critique, after a certain point there isn't anything different to learn than you would from just putting up the ones you're having the most difficulty with.
Well, even as a novice I can see that your monsters are looking a bit flat. You've darkened the colors on planes near the bottom, but there's little to no gradual shading; if burabura- for example- is supposed to be round, there should be increasingly dark shadows on the sides. Since it's round, its eyes should also look like they wrap around inside the main body, instead of looking like they're not even attached, or worse, flattening the facial area. Do you know what I mean?
Again, you can't expect people to "do it for you." You need to put some effort into it. And as for the "pointing out where you screwed up," that's exactly what they should be doing, and exactly what you should be asking for. To improve, you need to fix the bad first, and then enhance the good. The only thing stopping you from improving is yourself.Even though I try to get people to do this stuff for me, I usually get no reply... except from mods, maybe, and that tends to be to point out where I screwed up.
Not nearly as much, now. The eyes look like they're bulging outward a little, but I assume that's intentional. It fits your art style, in any case. Keep it up!