@Pl45m4 Yes im using a plain windows 10 system. And yes the linked bug is with MSys2 as i searched for a similar problem and this was the only thing related i could find. Found it odd myself that i worked inside qt creator but crashed outside (as said i tried windeploy and run dependency walker but haven't found a problem there) As said using llvm solves it for me but still wanted to point it out for others may experiencing something simlar. @Christian-Ehrlicher i posted all code above simply create a new project and add in my code for maindwindow.h and .cpp. There is nothing else in my project.

Just want to summarize the proposed solutions in an orderly fashion so that it remains for the future: @Christian-Ehrlicher: use QDate::addDays() / QDate::addMonths() / QDate::addYears(). [for dates] example: [qDateTime.setDate(qDateTime.date().addYears(XXX)] @JonB : write a global "utility" inline function to do a particular operation you want on a QDateTime. @J-Hilk: make a new class and inherit from QDateTime where you add those convenient setX functions. don't forget to convert the returning objects from the existing functions that return a QDateTime object to the new object, or make a constructor that excepts a QDateTime object as argument, that than can be done implicitly. Thank you all for a fruitful discussion and varied and helpful suggestions!

@Bonnie said in Showing timer in "hh:mm:ss.zzz" and reset when button clicked: I think QElapsedTimer is better for that situation. And instead of a static variable in a function, how about make it a member variable that can be used in other member functions. in the header, define a member variable of QElapsedTimer QElapsedTimer timer; in the slot function if(!timer.isValid()) timer.start(); QString formattedTime = QTime::fromMSecsSinceStartOfDay(timer.elapsed()).toString("hh:mm:ss.zzz"); when you "reset" the GUI timer.invalidate(); Thank you very much, that's exactly what I wanted :) Do you even have to pause and continue from there or just start and stop/reset? And yes, just start and stop/reset.

@The178 Hi On your first post [image: yTIrPw.png]

Ok solved It appears that a GLOBAL surface setInterval overrides the setIntervals I did on my glWidget. Kinda weird that the global one overrides local one if local one was specified, is this a bug ? format.setSwapInterval(0); QSurfaceFormat::setDefaultFormat(format); overrides on widget > QSurfaceFormat format; format.setSwapInterval(0); setFormat(format);

[SOLVED] MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { //… display = new QLabel(this); display->setGeometry(4,4,88,23); display->setText("00:00:00"); //… player = new QMediaPlayer; connect(player, SIGNAL(mediaStatusChanged(QMediaPlayer::MediaStatus)), this, SLOT(playerOnMediaStatusChanged(QMediaPlayer::MediaStatus))); //… timer = new QTimer; timer->setTimerType(Qt::PreciseTimer); connect(timer, SIGNAL(timeout()), this, SLOT(timerSlot())); //… } void MainWindow::playerOnMediaStatusChanged(QMediaPlayer::MediaStatus status) { if (status == QMediaPlayer::BufferedMedia) { pos = -1; //int pos declared on .h file timer->start(1000); } } void MainWindow::timerSlot() { pos = pos + 1; QTime time((pos/3600)%60, (pos/60)%60, pos%60); display->setText(time.toString("hh:mm:ss")); }

Thanks for you response

@SGaist said: should post this question to the development mailing list. You'll find the Qt's developers/maintainers (this forum is more user oriented) A discussion on this topic started on that mailing list yesterday, for those who are interested: http://comments.gmane.org/gmane.comp.lib.qt.devel/23437

@mrjj sorry, okay im now goign to SOLVED this thread thanks @SGaist @mrjj

@sirop It's set, I've checked it like this: void MainWindow::timerUpdate() { static int start = 0; static const size_t loops = 10000; static qint64 nsecs[loops]; static size_t index = 0; static QElapsedTimer* elapsed = new QElapsedTimer(); if(start++ < 10) { elapsed->restart(); qDebug() << "clockType: " << elapsed->clockType(); return; } if(index<loops) { nsecs[index++]=elapsed->nsecsElapsed(); elapsed->restart(); return; } timer->stop(); qint64 maxDev = 0; qint64 avgDev = 0; for( qint64 elapsedTime : nsecs ) { //qDebug() << "Time since last update" << elapsedTime << "nanoseconds"; qint64 dev = 5000000 - elapsedTime; if(dev < 0) { dev = dev*-1; } avgDev += dev; if( dev > maxDev) maxDev = dev; } qDebug() << "Max deviation: " << maxDev; qDebug() << "Avg deviation: " << avgDev/loops; } With following output: clockType: 4 Max deviation: 4615989 Avg deviation: 4327