FUN FACT: I don't. x3 Still working on that lol. I've only ever hit my target time like, twice? Even then, I still did something wrong. You don't have to hit a particular target time for shinies/natures though. But this one app, Pikatimer, really helps. You can google and download it, it comes in really handy.
Holymoly. Just watched some videos on how to RNG. :JKSDFDFJ: That just seems like a loooot of work. although advancing the frame seems a lot easier in HGSS, cause you just call elm like 10 or 3 times. idunno.
It's kinda complicated. You have to change the DS clock to a certain date, certain time, down to the second, press A to continue at a certain second, not take any longer than a certain amount of time from the intro to pressing continue, put the Pokemon in the daycare in the exact order, flip the journal pages a certain amount of times, no more, no less, etc.