@Anonymous wrote:
Some different ways of doing it:
1. Use excel to average the opening dates, then calculate number of months from the average date
2. Same as 1 but treat every opening date as the first of the month
3. Same as 1 but round the average date to the first of the month
4. Calculate the number of months for each card, average those months, and round down
5. Same as 4 but round up
6. Same as 4 but use the 1st of the month for each opening date
7. Same as 6 but round up
Thoughts?
I would like a calculation that exactly matches the result displayed on CCT. ASSUMING they do it right...
This is the sickness that comes to folks who spend too much time on myFICO.
Impossible to know short of access to the FICO algorithm.
Also it does round, and not always the way I think it reasonably should based on my own data. I've always made the assumption that it was calculated from the 1st of the month, as that's where I've seen changes in FICO 4 / 08 due to AAOA and historically open date doesn't always have an explicit date on it looking at bureau reports (some are just month/year though that might be changing like other things).
Honestly I wouldn't trust any third party implementation, not even Equifax's, let alone mine. The fact is in broad strokes it's close enough for government work, and that's really all the attention that should be paid to it. My score is pretty well flatlined now, maybe I can let some random balances report in a couple of months to drive score changes when I cross from 35 months to 36 months... problem is all my cards except 2 close on the same day, so I'm not really setup well to figure that out but I might be able to tease it out with some creative Chase payments since they'll mid-cycle update.
Have to see if I care enough haha.
An Excel worksheet works wonders:
