static final long MILI_SECONDS_PER_DAY = 86400000;
public static Date dateAfterNDays( Date startDate, int nDays)
{
if (startDate == null)
startDate = new Date(Date.getCurrentDate()); // assume today
Timestamp ts = startDate.timestampValue();
long nextDatesSecs = ts.getTime() + (MILI_SECONDS_PER_DAY * nDays);
return new Date( new Timestamp(nextDatesSecs));
}