This code determine today is in some duration.. based on KOREA locale
Calendar cstart = Calendar.getInstance(Locale.KOREA);
cstart.clear();
cstart.set(startyear, startmonth, startday);
Calendar cend = Calendar.getInstance(Locale.KOREA);
cend.clear();
cend.set(endyear, endmonth, endday);
Calendar c = Calendar.getInstance(Locale.KOREA);
if(c.after(cstart) && c.before(cend)) {
// today is in startyear/startmonth/startday ~ endyear/endmonth/endday
}