Описание тега qdatetime
A QDateTime is a class from the Qt toolkit which provides functions for working with both dates and times.
A QDateTime object is a combination of the QDate and QTime classes which contains information about a calendar date and clock time. It can read the current date and time from the system clock, and also provides functions for comparing, formatting and parsing date/times, and for performing basic date/time calculations.
The official documentation can be found here.