Online tax lien auctions

[Gautam P.]

I am following one of the online tax lien auction in Northern Jersey. I see that the auction start and end date is same. Can someone shed light on how these kind of auctions work. It is allowing me to enter % and premium (in NJ you bring down the Int rate to 0 and then if you badly need that lien you pay premium) and I can see number of bids on each property. But what I was expecting is that at the start of auction it is going to show me lowest interest rate bid (or premium) in real-time. How is that possible if auction start and end at the same time ? I am really confused. Without knowing what others are willing to offer, it is not open auction. Am I completely off.