Of course the hotel can change your date. But let's look at the big picture first...

The idea behind Priceline is not for the hotels and airlines to give away free money while playing bidding games. The idea is to sell high-quality inventory to people who would have otherwise purchased a low-quality product from a competitor at the same price.

In terms of their business plan, Priceline itself doesn't care if the airlines give you double upgrades on a different city pair on a different date. Priceline doesn't care if the hotel gives you the executive suite on December 31 instead of a regular room on August 15.

Giving people free changes and upgrades is a loss on the part of the airline and the hotel.

So, what it boils down to is this -- you want the hotel to change the date for free when the product that you purchased disallows that (in exchange for a lower price). It is no different from asking for a free upgrade (other than within the loyalty program), a date change to an almost sold-out date, or a complimentary second room for your friends.

I do not blame the hotels one iota for saying "no thanks" to a barrage of badgering that they give away the store.

------------------
"It's as easy as 1, 2, C" -- Kelly, Married With Children