The dates that were changed are just the date when they'll let you into the campground to get in line for the lineup.

A week or so later, they'll come around and give you a lineup number that determines the order in which you'll be allowed to move into the real campground (from the lineup holding areas) to choose your campsite for the actual festival.

A week before the festival actually starts, the landrush moves everyone into the actual campground.

Approximately a week after landrush, the festival starts, and runs for three or four days (depending on how you count them).

The dates for the festival itself haven't changed, so the performance dates/times for the stars will (mostly) go on according to the original schedule.

If you're not too particular about where you camp, there generally are a few good spaces available early on the day of the landrush; and if you don't need electricity there's always room even later to squeeze in another few tents - although you might not find space you can get to for a camper.

If you have a group that wants to camp together in a particular spot, somebody has to occupy a space in the lineup close enough to the front of the line to "secure" the campsite, which generally means "marking a spot" in the prelineup area about 30 days in advance of the festival. Most people mark their prelineup spot with a tent or a camper, but only a few actually "camp" prior to landrush, and any marker you can stick a receipt on for the prelineup camping days will work. (Markers have ranged from a stake in the ground, to staked down tarps and to porcelain thrones and old sofas from the thrift shop.)

To get a lineup number you have to be present when they hand them out (because that's when you pay the camping fees through the end of the festival), and of course to get your camping spot you have to participate in the landrush (successfully); but otherwise you only have to "be there" when you want to.

John