Write SQL query to solve given problem: Among all the orders made by Aimee Bixby, what was the longest shipment time?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT MAX(strftime('%J', `Ship Date`) - strftime('%J', `Order Date`)) AS longestTimeDays FROM people AS T1 INNER JOIN central_superstore AS T2 ON T1.`Customer ID` = T2.`Customer ID` WHERE T1.`Customer Name` = 'Aimee Bixby'