Easy way to get day number of current quarter?

How about:

$curMonth = date("m", time());
$curQuarter = ceil($curMonth/3);

I wrote a class with the following methods. Enjoy.

public static function getQuarterByMonth($monthNumber) {
  return floor(($monthNumber - 1) / 3) + 1;
}

public static function getQuarterDay($monthNumber, $dayNumber, $yearNumber) {
  $quarterDayNumber = 0;
  $dayCountByMonth = array();

  $startMonthNumber = ((self::getQuarterByMonth($monthNumber) - 1) * 3) + 1;

  // Calculate the number of days in each month.
  for ($i=1; $i<=12; $i++) {
    $dayCountByMonth[$i] = date("t", strtotime($yearNumber . "-" . $i . "-01"));
  }

  for ($i=$startMonthNumber; $i<=$monthNumber-1; $i++) {
    $quarterDayNumber += $dayCountByMonth[$i];
  }

  $quarterDayNumber += $dayNumber;

  return $quarterDayNumber;
}

public static function getCurrentQuarterDay() {
  return self::getQuarterDay(date('n'), date('j'), date('Y'));
}

function date_quarter()
{
    return ceil(date('n', time()) / 3);
}

or

function date_quarter()
{
    $month = date('n');

    if ($month <= 3) return 1;
    if ($month <= 6) return 2;
    if ($month <= 9) return 3;

    return 4;
}