By default the class QDateEdit accepts dates in the range September 14, 1752 through December 31, 7999. However this range can be changed by simply using the setMinimumDate (concst QDate & min) or the setDateRange (const QDate & min, const QDate & max)
For example, with setDateRange it would look something like this:
QDateEdit dtE;
QDate minDate(1500, 1, 1);
QDate maxDate(1600, 12, 31);
dtE.setDateRange(mindDate, maxDate);
From the 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.