There's been a few forum posts about the countdown clock and the usual advice is to set the time on your computer to the right time zone. 

Time and time zone, not just the time zone. Time zone errors will cause the auction time ending shown in search results to be off by a number of hours. Time errors will cause problems bidding at the end of the auction if your device's time is not synchronized to an internet time server.

I have absolutely no idea how to do this

In Windows, try right clicking on the clock in your task bar, choose "Adjust date/time", then use the options to set time and time zone automatically. For other operating systems use Google to search your own operating system version along with the keywords "set time automatically".