DateUtil { public static int getDaysInMonth(Calendar calendar) { return getDaysInMonth(new DateTime(calendar)); } private  DateUtil(); static int getWeekNumberForDate(Date date, int configuredFirstDayOfWeek); static void dayOfWeekFix(Calendar calendar); static boolean isWeekend(Calendar calendar); static int getDaysInMonth(Calendar calendar); static int getDaysInMonth(DateTime calendar); static DateRange calendarToMonthRange(Calendar calendar); static boolean isDateWithinRange(Date date, DateRange dateRange); static boolean isDateWithinRange(DateTime date, DateRange dateRange); static boolean isDateWithinRange(Calendar calendar, DateRange dateRange); static boolean isDateRangeOverlaps(DateRange rangeA, DateRange rangeB); static DateRange getDateRangeForWeek(Calendar calendar); static DateRange getDateRangeForMonth(Date date); static DateRange getDateRangeForMonth(Calendar calendar); static DateRange getDateRangeForQuarter(Calendar calendar); static Calendar addQuarter(Calendar calendar, int quarterDelta); static Date nullifyTime(Date date); static void nullifyTime(Calendar cal); static void maximizeTime(Calendar cal); static Date maximizeTime(Date date); static List<Date> createDateSequence(DateRange range, EhourConfig config); static Calendar getCalendar(EhourConfig config); static Calendar getCalendar(Date date); static String getPatternForDateLocale(Locale dateLocale); static String formatDate(Date date, Locale dateLocale); static String formatDate(DateTime date, Locale dateLocale); static String formatDate(LocalDate date, Locale dateLocale); static int fromCalendarToJodaTimeDayInWeek(int dayInWeek);  }
@Test public void should_return_31_days_as_amount_of_days_in_January() { assertEquals(31, DateUtil.getDaysInMonth(new GregorianCalendar(2012, 0, 15))); }
@Test public void should_return_29_days_as_amount_of_days_in_February_2012() { assertEquals(29, DateUtil.getDaysInMonth(new GregorianCalendar(2012, 1, 15))); }
@Test public void testGetDaysInMonth() { Calendar cal = new GregorianCalendar(2006, 11 - 1, 4); assertEquals(30, DateUtil.getDaysInMonth(cal)); cal = new GregorianCalendar(2007, 2 - 1, 5); assertEquals(28, DateUtil.getDaysInMonth(cal)); }
@Test public void testGetDaysInMonthJoda() { DateTime date = new DateTime(2006, 11, 4, 0, 0, 0, 0); assertEquals(30, DateUtil.getDaysInMonth(date)); date = new DateTime(2007, 2, 5, 0, 0, 0, 0); assertEquals(28, DateUtil.getDaysInMonth(date)); }