Yes the difference sure is the time zone. The JavaScript code takes your system time and compares it with the future time, so the result will always be the date and time of your current destination. To compensate you have to add or subtract the offset hours to the country or timezone you want to have.

Even if you compare different online counters for that election date they often show different values. Some code takes the time of the server location, other take your system time and other have fixed the time for that certain timezone they want the countdown for.

Best Michel