I agree this is very confusing, and the designer companies contribute to it. I received a card in the mail from BV saying their US boutiques' sale would begin Dec. 3rd. I call Chicago, the only BV store I've been in, and they told me they'd already started their "private" sale!! I've spend thousands of dollars there but apparently don't qualify for their private sale! On the website, I don't know when the sale prices were posted.
Same deal with Neiman's--they will pre-sell a bag that officially goes on sale later. So if you wait till it's announced, it's too late to get anything good.
I feel your pain! Wish there was a better system. guess we're fortunate BV puts anything on sale--some brands never do.