Well, in my OLD Pearl, I reset 12,000 times, and didn't get anything
12,000 times takes about 120 hours.
And NOTHING showed up.
So I scrapped it.
I was hunting a Dialga, and then I got bored after about 1,500.
So then I went onward to Uxie, and after 12 resets, it shone! I was surprised that it shone so quickly, but it was VERY exciting, as I had never gotten a SR shiny before, and the fact that it appeared in an almost record-breaking time.