By default the class Qdateedit accepts dates in the range 14 September 1752 until 31 December 7999. However, this range can be changed by simply using the method setMinimumDate(const Qdate &min) or the method setDateRange(const Qdate &min, const Qdate &max)
For example, with setDateRange it would be something like this:
QDateEdit dtE;
QDate minDate(1500, 1, 1);
QDate maxDate(1600, 12, 31);
dtE.setDateRange(mindDate, maxDate);
Of documentation
By default, this Property contains a date that refers to September 14,
1752. The minimum date must be at least the first day in year 100, otherwise setMinimumDate() has no Effect.