For new credit to become old? That is, I've read that the length of time you've had a credit account counts in your score, so that young credit counts against you but older credit gives a higher score, right? So at what point does a new account start to work for my credit score?
It goes month by month, each month "adds" to your history. SO, in the beginning you'll gain more than later on. There is no "breakpoint", of new vs old. The "seasoning" progresses month by month. This is one of the hradest parts of improving your scores. You simply must let time pass, and resist the temptation to open new accounts as your credit improves. Also, do not close good accounts that still report.