+------------------------------------------++-------------------------------------------------------+
              |                  DAILY                   ||                       MONTHLY                         |
+-------------+-------+-------+----------+-------+-------++-------+------------+-------+----------+-------+-------+
| Creator     | Count |  Time |  Average |  Min. |  Max. || Count | Daily Avg. |  Time |  Average |  Min. |  Max. |
+-------------+-------+-------+----------+-------+-------++-------+------------+-------+----------+-------+-------+
| williamsonb |    42 |  3:56 | 00:08:34 | 00:02 | 00:34 ||   ... |        ... |   ... |      ... |   ... |   ... |
| petersonl   |   ... |   ... |      ... |   ... |   ... ||   ... |        ... |   ... |      ... |   ... |   ... |
| ...         |   ... |   ... |      ... |   ... |   ... ||   ... |        ... |   ... |      ... |   ... |   ... |
+-------------+-------+-------+----------+-------+-------++-------+------------+-------+----------+-------+-------+

CREATE TABLE
    WorkOrders
        (CreatedBy CHAR(25)
        ,CreatedTime DATETIME)

INSERT INTO
    WorkOrders
        (williamsonb, 03/26/2017 12:05:00.000 PM)
        ;(williamsonb, 03/26/2017 12:12:00.000 PM)
        ;(williamsonb, 03/26/2017 01:31:00.000 PM)
        ;(williamsonb, 03/02/2017 09:45:00.000 AM)
        ;(williamsonb, 03/02/2017 09:49:00.000 AM)
        ;(williamsonb, 03/02/2017 09:51:00.000 AM)
        ;(williamsonb, 02/04/2017 02:14:00.000 PM)
        ;(petersonl, 03/26/2017 07:42:00.000 AM)
        ;(petersonl, 03/26/2017 07:45:00.000 AM)
        ;(petersonl, 03/26/2017 07:46:00.000 AM)
        ;(petersonl, 03/05/2017 08:47:00.000 AM)
        ;(petersonl, 03/05/2017 08:49:00.000 AM)
        ;(petersonl, 03/05/2017 08:50:00.000 AM)
        ;(petersonl, 01/17/2017 06:54:00.000 AM)

DECLARE
    @DayCount INT =
        COUNT(
            SELECT
                CreatedBy

            FROM
                WorkOrders

            WHERE
                CreatedTime =
                    DATEADD(DAY,-1,GETDATE())
    ,@DayTimeSum DECIMAL = SUM(DATEDIFF(HOUR,SELECT(HOUR(CreatedTime) FROM WorkOrders WHERE DATEADD(DAY,-1,GETDATE()) ) + DATEDIFF(MINUTE,SELECT(MINUTE(CreationDate)/60 FROM WorkOrders WHERE DATEADD(DAY,-1,GETDATE()) ) + DATEDIFF(SECOND,SELECT(SECOND(CreationDate)/3600 FROM WorkOrders WHERE DATEADD(DAY,-1,GETDATE()) )
)
    ,@DaySumHours INT = @DayTimeSum - MOD(@DayTimeSum % 1)
    ,@DaySumMinutes INT = (MOD(@DayTimeSum % 1) - MOD(MOD(@DayTimeSum % 1) % 1/60) ) * 60
    ,@DayAvgTime DECIMAL = @DayCount / @DayTimeSum
    ,@DayAvgHours INT = @DayAvgTime - MOD(@DayAvgTime % 1)
    ,@DayAvgMinutes INT = (MOD(@DayAvgTime % 1) - MOD(MOD(@DayAvgTime % 1) % 1/60) ) * 60
    ,@DayAvgSeconds INT = ( (MOD(@DayAvgTime % 1) - MOD(MOD(@DayAvgTime % 1) % 1/60) ) - MOD((MOD(@DayAvgTime % 1) - MOD(MOD(@DayAvgTime % 1) % 1/60) ) % 1/3600) ) * 3600
    ,@MonthTimeSum DECIMAL = SUM(DATEDIFF(HOUR,SELECT(HOUR(CreatedTime) FROM WorkOrders WHERE DATEADD(MONTH,-1,GETDATE()) ) + DATEDIFF(MINUTE,SELECT(MINUTE(CreationDate)/60 FROM WorkOrders WHERE DATEADD(MONTH,-1,GETDATE()) ) + DATEDIFF(SECOND,SELECT(SECOND(CreationDate)/3600 FROM WorkOrders WHERE DATEADD(MONTH,-1,GETDATE()) )
)

SELECT
    DISTINCT CreatedBy
    ,@DayCount AS [Count]
    ,@DaySumHours + ':' + @DaySumMinutes + ':' + @DaySumSeconds AS [Total]
    ,@DayAvgHours + ':' + @DayAvgMinutes + ':' + @DayAvgSeconds AS [Average]
    ,LAST(SELECT
        CAST(SELECT CAST(CreatedTime AS TIME) AS CHAR(5))) AS [Min.]
    ,TOP 1(CAST(SELECT CAST(CreatedTime AS TIME) AS CHAR(5))) AS [Max.]

FROM
    WorkOrders

WHERE
CreatedTime BETWEEN DATEADD(MONTH,-1,GETDATE()) AND GETDATE()

GROUP BY
    CreatedBy

ORDER BY
    CreatedTime DESC