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!

Hi
If the database table type is of type date, it wont like a string formatted as
SunFeb2020 so you need to match the toString format to the one expceted by the DBMS.

@the_ @SGaist Hi, I managed to solve it on my own by encoding the date to a JulianDate and using juliandate on my db so it's much easier to compare and so.

Thanks for your help.

@asanka424
Thank you.

Thank you very much :-)

@RDiGuida To add to @Mario84's answer, QString is Qt based class and your using standard c++ API's to print it which it doesnot understand. To print values of pure Qt based API's you can use qDebug().
Eg:

QString dt ((dates[0]).toString()); qDebug() << dt;