public int quarter() {
		return month() / 3 + 1;
	}
@Test
	public void quarterTest() {
		DateTime dateTime = new DateTime("2017-01-05 12:34:23", DatePattern.NORM_DATETIME_FORMAT);
		Quarter quarter = dateTime.quarterEnum();
		assertEquals(Quarter.Q1, quarter);

		dateTime = new DateTime("2017-04-05 12:34:23", DatePattern.NORM_DATETIME_FORMAT);
		quarter = dateTime.quarterEnum();
		assertEquals(Quarter.Q2, quarter);

		dateTime = new DateTime("2017-07-05 12:34:23", DatePattern.NORM_DATETIME_FORMAT);
		quarter = dateTime.quarterEnum();
		assertEquals(Quarter.Q3, quarter);

		dateTime = new DateTime("2017-10-05 12:34:23", DatePattern.NORM_DATETIME_FORMAT);
		quarter = dateTime.quarterEnum();
		assertEquals(Quarter.Q4, quarter);

		// 精确到毫秒
		DateTime beginTime = new DateTime("2017-10-01 00:00:00.000", DatePattern.NORM_DATETIME_MS_FORMAT);
		dateTime = DateUtil.beginOfQuarter(dateTime);
		assertEquals(beginTime, dateTime);

		// 精确到毫秒
		DateTime endTime = new DateTime("2017-12-31 23:59:59.999", DatePattern.NORM_DATETIME_MS_FORMAT);
		dateTime = DateUtil.endOfQuarter(dateTime);
		assertEquals(endTime, dateTime);
	}