For some unknown reason eBay no longer displays the ending time to the second at the top of the bid history page, but if there are any bids you should be able to calculate the actual ending time by examining the starting time of the auction at the bottom of the page. Auctions always begin and end at the same time down to the exact second, unless the auction is ended early by the seller. All bidders have the same time to place valid bids, and no one gets any extra time. eBay time stamps every bid as it is received by eBay, and the times are displayed to the second in the bid history if you use a desktop browser.
If you think you have encountered an auction where a bid was accepted after the end of the auction, examine the starting time closely and compare it to the time the bid was received and you should find that the bid was received before the auction actually ended. If not, please post an item number so that others can see it.
If you bid the maximum amount you are willing to pay (taking into account any shipping or taxes) then the only way you can lose is if someone is willing to bid more than you were and actually does so, or if someone bid the same exact amount, earlier.
No one can count on having the last bid, and bidders should assume that other bids will be placed at the end of the auction too late to be reacted to, and set their bids accordingly. Note that the countdown displayed on your device and the bids you see are not updated in real time, and just because you did not see any other bids when your clock reaches zero does not mean that eBay did not receive other bids at the last moment.
You have not won until the page refreshes and you see a note indicating that you have been declared the winner and you see a link to pay or your payment is take automatically. A note indicating you are the high bidder issued while the auction is still ongoing is not the same as being declared the winner by eBay after the auction has ended.
If your auction countdown is not behaving correctly, check to make sure your computer's time and time zone are set correctly, and the date and time are synchronized with an internet time server such as time.windows.com or time.gov.
Check your computer's time here:
https://time.is/
If your computer's time is too fast or too slow, that can prevent you from bidding at the end of an auction. Either your computer will think the auction is over when it is not, preventing you from bidding, or else you will think you have more time left when the auction is about to end. Neither situation helps you. Set your computer's time to automatically synchronize to prevent this from happening.
