The problem is that any time you talking about creating backlinks, what you're effectively doing is promoting your own website ... and Google couldn't care less about that. It doesn't matter if you create one link a day or a thousand, if Google thinks that you have planted those links yourself, they won't make a blind bit of difference.
As to what speed the backlinks appear at – that depends. If it's a sudden trending topic then it may be perfectly reasonable to have thousands of links, shares, likes and tweets springing up in a day. If there's no obvious reason for the explosion in activity then Google is likely to just see it as spam. Ultimately, there is no fixed number. Because any time there's a fixed number, it becomes too easy for people to game the system and subvert the rules, which is exactly what Google does not want to happen.
Rather than just plucking numbers out of the air, how about giving some reason or rationale where those numbers come from?