Convert day of the year to date with QT

I am facing an issue, the API that I am using return the year and the day of the year. For example : year = 2020 & day = 328 and I should be able to convert it to 24/11/2020. I saw that QT implements a method called "daysInYear" in QDate which looks like to do the exact opposite of what I need. Does anyone knows a method in QT or Cpp11+ which can do the job ? Thanks in advance