//getTime_log() returns vector of QDateTime object

std::vector<Student>::iterator siter;
std::vector<QDateTime>::const_iterator iterqdt;

for ( iterqdt = siter->getTime_log().cbegin(); iterqdt != siter->getTime_log().cend(); iterqdt++ )
{
                             ui->timeLogList->addItem(iterqdt->time().toString("hh::mm::ss a")+
                                                      "   "+QString::number(iterqdt->date().month()) +
                                                      "/"+QString::number(iterqdt->date().day()) + "/" +
                                                      QString::number(iterqdt->date().year()) + "   " +
                                                      QDate::longDayName(iterqdt->date().dayOfWeek()));
}