public static <D extends Comparable> DateTimeExpression<D> dateadd(DatePart unit, DateTimeExpression<D> date, int amount) {
        return Expressions.dateTimeOperation(date.getType(), DATE_ADD_OPS.get(unit), date, ConstantImpl.create(amount));
    }
Create a dateadd(unit, date, amount) expression

@param unit date part
@param date date
@param amount amount
@return converted date
querydsl-sql/src/main/java/com/querydsl/sql/SQLExpressions.java