The only use of/reference to “timezone” I can find in the base plugin is line 324 in the Post_Views_Counter_Dashboard class.
// get current date
$current_date = date_create( 'now', wp_timezone() )->format('Y m W d t');
$current_date_chunks = explode( ' ', $current_date );
Neither of those variables are used anywhere else.
Using wp_timezone() on my site outputs the correct date and time according to the timezone set in WP settings. So, if that code was used anywhere, it would produce an accurate time.
Haven’t been through the JS yet.