Someone had emailed me with a similar question. Tried to find my response, but couldn't. Here's a roundabout what I said…..
Yes, it takes time. J.D. and I have "known" each other for several years. I've already guest posted on his site in the past. When his book came out he advanced me a copy to see if a "CFP" would find any flaws in it. We also both do Crossfit :)
I'm not saying this to brag, just to show you that we have some history together.
When I emailed him about my previous guest post idea, he had said that it might actually go live the following week – I was blown away! I guess he didn't expect another post to be done in time but it did. From the day that I first contacted him about the post, it took just about 3 months to get published.
If I recall, I gave him a nudge or 2 (I think just one) just making sure he thought the post was still a good fit for his site. He responded fairly quickly and reassured me it would go up.
They have so much content that I suspect that they could schedule out 3 months in advance 7 days a week (and probably longer).
Good luck!!