Question

I have a function that returns a QDateTime class, with the following code:

QDateTime Foo:IntToQDateTime( int Date )
{
    int Second = 4,
        Minute = 3,
        Hour   = 22,
        Day    = 10,
        Month  = 11,
        Year   = 2011;
    QDate d(Year, Month, Day);
    QTime t(Hour, Minute, Second);
    QDateTime r(d, t);
    return r;
}

That produces r with null strings/time_t of 4294967295, yet d and t are both accurate.

If I change the code to:

QDateTime Foo:IntToQDateTime( int Date )
{
    int Second = 4,
        Minute = 3,
        Hour   = 22,
        Day    = 10,
        Month  = 11,
        Year   = 2011;
    QDate d(Year, Month, Day);    // November 11 2011
    QTime t(Hour, Minute, Second);// 22:03:04:00
    QDateTime r(QDate(Year, Month, Day), QTime(Hour, Minute, Second));
    return r;
}

r is now “Fri Nov 8 00:56:47 16182” with a time_t of 4294967295 (same as above). Can anyone explain to me why a.) the date/time is inaccurate for the QDateTime class r, and why b.) passing d and t as apposed to QDate(...), QTime(...) in the constructor also affects the date/time.

Answer 1

How did you determine the values you reported?

With this program:

#include <QCoreApplication>
#include <QDebug>
#include <QDate>
#include <QTime>

QDateTime IntToQDateTime( int Date )
{
    int Second = 4,
        Minute = 3,
        Hour   = 22,
        Day    = 10,
        Month  = 11,
        Year   = 2011;
    QDate d(Year, Month, Day);
    QTime t(Hour, Minute, Second);
    QDateTime r(d, t);
    return r;
}

int main(int argc, char** argv)
{
  QCoreApplication a(argc, argv);
  QDateTime t = IntToQDateTime(0);
  qDebug() << t.toTime_t();
  qDebug() << t.toString();
  return 0;
}

I get the following output with Qt 4-8.0, MSVC-2010-Express, German Windows7/64:

1320958984
"Do 10. Nov 22:03:04 2011"

Are you sure that your environment is correct and that you do not see some artefact of debugging?