live in switzerland where penny/1 cent is nonexistant, so i need to find a way to get the TVA VAT tax to automaticall round to the nearest .0 or .5 or .55. does anyone have some advice?
found this block of code in functions and also simlar in classes and it seems like it could be here to find a solution but after a few tests can't figure it out:

// Calculates Tax rounding the result
function zen_calculate_tax($price, $tax) {
global $currencies;
// $result = bcmul($price, $tax, $currencies->currencies[DEFAULT_CURRENCY]['decimal_places']);
// $result = bcdiv($result, 100, $currencies->currencies[DEFAULT_CURRENCY]['decimal_places']);
// return $result;
return zen_round($price * $tax / 100, $currencies->currencies[DEFAULT_CURRENCY]['decimal_places']);
}