Has anyone experimented with using west coast or Hawaiian based vpn servers to book flights and extend a sale deadline? If a sale expires at midnight, and I miss it by a few minutes, can I use a west coast vpn server location to still get the sale price? I'm wondering if it's worth finding a vpn with a Hawaiian server to explore this. I've missed several fare deals when booking late at night and not completing by midnight.

Not likely. Most sales (and most other things online that have a specific end time) end at a particular time in a particular time zone (eg, ends at midnight CST = Central Standard Time). That's usually stated somewhere, sometimes in the "headline" part of the sale info, sometimes only in the fine print. So no matter where you are, they end at the same moment, even if that moment is shown as different time in other time zones.

And, in fact, you should always pay attention to that if you're going to cut it that close, because if the sale ends at midnight in a time zone east of you, then it ends an hour or more before midnight in your time zone!

The time zones used for sale ends vary. In some cases they're arbitrary, in other cases they're simply the time zone where the company is based. So a company based on the west coast might end the sale based on Pacific time, while a company based in the middle of the country may end the sale based on Central time, etc.

I think you mean east. Midnight in Chicago is 1am in New York.