/** * Creates a new date by adding the specified number of months to the base date. * * <p>If the base date is close to the end of the month, the day on the result may be adjusted * slightly: 31 May + 1 month = 30 June. * * @param months the number of months to add (can be negative). * @param base the base date. * @return a new date. */ public static SerialDate addMonths(final int months, final SerialDate base) { final int yy = (12 * base.getYYYY() + base.getMonth() + months - 1) / 12; final int mm = (12 * base.getYYYY() + base.getMonth() + months - 1) % 12 + 1; final int dd = Math.min(base.getDayOfMonth(), SerialDate.lastDayOfMonth(mm, yy)); return SerialDate.createInstance(dd, mm, yy); }
/** * Creates a new date by adding the specified number of years to the base date. * * @param years the number of years to add (can be negative). * @param base the base date. * @return A new date. */ public static SerialDate addYears(final int years, final SerialDate base) { final int baseY = base.getYYYY(); final int baseM = base.getMonth(); final int baseD = base.getDayOfMonth(); final int targetY = baseY + years; final int targetD = Math.min(baseD, SerialDate.lastDayOfMonth(baseM, targetY)); return SerialDate.createInstance(targetD, baseM, targetY); }