QDateEdit will show three-digit value for date with the following scenario:

• QDateEdit has the display format set to ‘yyyy/MM/dd’
• the date value is edited to ‘31’
• focus is changed to month with Shift + Tab
• the month value is edited to ‘2’
  -> the date value shows ‘291’ until cursor is moved or focus changed.

The QDateTimeParser seems to calculate the section size incorrectly (sectionSize() returns 1) therefore the date is replaced incorrectly. In QDateTimeParser::StateNode QDateTimeParser::parse(QString &input, int &cursorPosition, const QDateTime &currentValue, bool fixup) method the 'input' has the three-digit day, but the 'newCurrentValue' has the correct date.