In my experience, it took up to a month, but perhaps less, before it showed up. I regularly check my credit record through my bank's website, but I didn't check it for about a month after I got the OpenSky card. The information about the card, its limit, balance, percentage of credit used, etc... was already there after that one month. So it could have been reported sooner than that, but I wasn't checking sooner than that.

I got this card for my daughter exactly on her 18th birthday 12/2017 and as of today, which is 05/2018, she has a 680 credit score. I would say the score was reported 4 to 4.5 months in.