SELECT 
        Task_ID, 
        Start_Date, 
        End_Date, 
        DATE_SUB(Start_Date, INTERVAL ROW_NUMBER() OVER (ORDER BY Start_Date) DAY) AS PGroup
    FROM Projects
)
SELECT 
    MIN(Start_Date) AS PStart, 
    MAX(End_Date) AS PEnd
FROM PSEQ
GROUP BY PGroup
ORDER BY DATEDIFF(MAX(End_Date), MIN(Start_Date)), MIN(Start_Date);