SELECT
    roundtime AS `Round Time`,
    sInduction_Name AS `Induction Name`,
    COUNT(*) AS `Inducted`
FROM (
    SELECT
        FROM_UNIXTIME(
            FLOOR(UNIX_TIMESTAMP(t_stamp) / 
                CEIL(TIMESTAMPDIFF(SECOND, :starttime, :endtime) / 24.0)
            ) * 
            CEIL(TIMESTAMPDIFF(SECOND, :starttime, :endtime) / 24.0)
        ) AS roundtime,
        'S03' AS sInduction_Name
    FROM item_data
    WHERE t_stamp BETWEEN :starttime AND :endtime
        AND adiSort_Code_0 NOT IN (11, 15)
        AND sLocation_ID LIKE 'S03%'
        AND (COALESCE(:inductionname, '') = '' OR :inductionname = 'S03')
) AS x
GROUP BY roundtime, sInduction_Name
ORDER BY roundtime ASC;