public NumberExpression<Integer> dayOfYear() {
        if (dayOfYear == null) {
            dayOfYear = Expressions.numberOperation(Integer.class, Ops.DateTimeOps.DAY_OF_YEAR, mixin);
        }
        return dayOfYear;
    }
Create a day of year expression (range 1-356)
<p>NOT supported in JDOQL and not in Derby</p>

@return day of year
querydsl-core/src/main/java/com/querydsl/core/types/dsl/DateExpression.java