DTBuilder dtStartMinus1B = new DTBuilder(dtStart);
dtStartMinus1B.day -= interval;
DateValue dtStartMinus1 = dtStartMinus1B.toDate();
year = dtStartMinus1.year();
month = dtStartMinus1.month();
date = dtStartMinus1.day();
nDays = TimeUtils.monthLength(year, month);
}
@Override
boolean generate(DTBuilder builder) {