For Hilton, there's a bunch of different booking windows. I'm paraphrasing here as you'll get way more info on the HGV forums.
For non-"by hilton club" locations, the owners home-week is bookable 12-months in advance (each resort has its own home-week check-in date). Club bookings (ie, you're NOT using your home week, even if you're booking at the resort that you "own" at), those are 9-months in advance.
If you don't own at by hilton club, you can book 60 days in advance. (ie: W57th in NYC, etc.)
There are some resorts that you *cannot* book period unless you own there (Hilton Club in NYC I believe is one).
When you buy HGV (regardless of whether resale or direct) you're buying a deeded week in a specific unit size. HGV doesn't guarantee you can actually book said unit, BTW. That unit size (and the points required) is your "home week". For example, a 2 BR Las Vegas Blvd week in Platinum Season is 7,000 "club points". If you want to book your home week, it's bookable 12 months in advance and it uses ALL your 7,000 points for an entire week in a 2 BR unit. You cannot book a smaller sized unit, nor can you book a shorter/longer stay using Home Week.
However, if you're willing to book only 9-months in advance, you can use Club Points (ie, you have 7,000 points). You can still book a 2 BR during Platinum season at "your" resort. However, if you wanted to book a 2 BR in say Gold season, it may only cost you 4,800 points. You can book elsewhere (ie, Orlando or Hawaii).
To be fair:
I've never had much of an issue booking 9-months in advance. Even for Hawaii. You may need to be up at midnight Eastern Time to secure your week or book a 3-night stay and slowly add nights as other folks are "walking" their reservation.
For by hilton club though, I would say you have a very slim chance that for NYC you will not get an entire 1-week at 60-days. You can probably get 3-5 nights, but it depends on WHEN. (ie, I highly doubt you'd ever see 5+ nights available during December at only 60-days prior).
For Hiton this is why "we" recommend to buy where you want to stay the most often (unless you're willing to be very flexible).
There's some resorts in Hawaii that have other/odd booking windows.
Most folks I see on the FB pages for HGV that complain about booking are either booking things way too late (like try to get Christmas week 3 months in advance--not gonna happen probably). Or it's a very new resort (Barbados) with very limited inventory (Hilton is building more buildings).
Again, this is the "short" version (LOL).
Hilton doesn't treat resale any different than direct (for now). So you have the same booking windows whether you buy direct or resale.
It's where you *own* that gives you the farthest ahead booking window.
Also note that you can buy FIXED weeks (vs. floating weeks). Not easy to find on resale market, that I've seen. (ie, you really want say, Christmas week 52 in XXXX) you can buy that week. You'd still have your club points booking option AFAIK.
Those would usually come at a premium (unless it's an affiliate).
But I digest.