NepaliCalendar extends AbstractCalendar { @Override public DateTimeUnit plusDays( DateTimeUnit dateTimeUnit, int days ) { if ( days < 0 ) { return minusDays( dateTimeUnit, Math.abs( days ) ); } int curYear = dateTimeUnit.getYear(); int curMonth = dateTimeUnit.getMonth(); int curDay = dateTimeUnit.getDay(); int dayOfWeek = dateTimeUnit.getDayOfWeek(); while ( days != 0 ) { int dm = CONVERSION_MAP.get( curYear )[curMonth]; curDay++; if ( curDay > dm ) { curMonth++; curDay = 1; } if ( curMonth > 12 ) { curYear++; curMonth = 1; } dayOfWeek++; if ( dayOfWeek > 7 ) { dayOfWeek = 1; } days--; } return new DateTimeUnit( curYear, curMonth, curDay, dayOfWeek ); }  static Calendar getInstance(); @Override String name(); @Override DateTimeUnit toIso( DateTimeUnit dateTimeUnit ); @Override DateTimeUnit fromIso( Date date ); @Override DateTimeUnit fromIso( DateTimeUnit dateTimeUnit ); @Override DateInterval toInterval( DateTimeUnit dateTimeUnit, DateIntervalType type, int offset, int length ); @Override int daysInYear( int year ); @Override int daysInMonth( int year, int month ); @Override int weeksInYear( int year ); @Override int isoWeek( DateTimeUnit dateTimeUnit ); @Override int week( DateTimeUnit dateTimeUnit ); @Override int isoWeekday( DateTimeUnit dateTimeUnit ); @Override int weekday( DateTimeUnit dateTimeUnit ); @Override String nameOfMonth( int month ); @Override String shortNameOfMonth( int month ); @Override String nameOfDay( int day ); @Override String shortNameOfDay( int day ); @Override DateTimeUnit minusYears( DateTimeUnit dateTimeUnit, int years ); @Override DateTimeUnit minusMonths( DateTimeUnit dateTimeUnit, int months ); @Override DateTimeUnit minusWeeks( DateTimeUnit dateTimeUnit, int weeks ); @Override DateTimeUnit minusDays( DateTimeUnit dateTimeUnit, int days ); @Override DateTimeUnit plusYears( DateTimeUnit dateTimeUnit, int years ); @Override DateTimeUnit plusMonths( DateTimeUnit dateTimeUnit, int months ); @Override DateTimeUnit plusWeeks( DateTimeUnit dateTimeUnit, int weeks ); @Override DateTimeUnit plusDays( DateTimeUnit dateTimeUnit, int days ); @Override DateTimeUnit isoStartOfYear( int year );  }
@Test public void testPlusDays() { DateTimeUnit dateTimeUnit = new DateTimeUnit( 2014, 12, 30 ); DateTimeUnit testDateTimeUnit = calendar.plusDays( dateTimeUnit, -1 ); assertEquals( 2014, testDateTimeUnit.getYear() ); assertEquals( 12, testDateTimeUnit.getMonth() ); assertEquals( 29, testDateTimeUnit.getDay() ); dateTimeUnit = new DateTimeUnit( 2014, 1, 1 ); testDateTimeUnit = calendar.plusDays( dateTimeUnit, - 1 ); assertEquals( 2013, testDateTimeUnit.getYear() ); assertEquals( 12, testDateTimeUnit.getMonth() ); assertEquals( 30, testDateTimeUnit.getDay() ); }