Sounds like it can vary by state. In California the window opens at 8AM Pacific time on the 1st of each month except January which would be the 2nd. This window is for the entire new month. For example on October 1 the window that opened was for April 1-30.
Best thing would be to check RA website or call them to find out the actual date range for the state and/or campground you are interested in.
You can also *test the system* to see how far out you can book. If you are beyond the current open dates it won't allow you to book them. On the other hand if you are in the open window a credit card will be needed to complete the transaction but you would opt out of that screen & let the dates return to the system. After all no payment = no reservations.
Great choice for "Living within my means" and camping for one...
2011 Salem Cruise Lite 20RBXL & 2011 Toyota Tundra Dbl Cab
Camping History: 45 Trips / 133 Nights / 3736 Miles
Being on the Coast Guard, 2-3 months out is as far as I can plan. I will have to assume that we are lucky. Never had much of an issue, except Fall Creek Falls, TN. They are half reservation half not. We would drive up in the car Thursday morning to try and get a spot.
Remember that you can cancel, too. I often reserve with the thought that we will stay but sometimes need to cancel (for a small cancellation fee). Its too bad that it needs to be done this way, but some places are really hard to get into.
DW, 3 Kids and our Goldens
2012 Shamrock 233S
2008 Toyota Sequoia 5.7L 4WD