from 15 minutes interval to hourly interval counts - sql

Question

am using excel sheet to display data from sql with this query
SELECT itable.Timestamp, itable.Time,
Sum(itable.CallsOffered)AS CallsOffered, Sum(itable.CallsAnswered)AS CallsAnswered, Sum(itable.CallsAnsweredAftThreshold)AS CallsAnsweredAftThreshold,
sum(CallsAnsweredDelay)AS CallsAnsweredDelay
FROM tablename itable
WHERE
(itable.Timestamp>=?) AND (itable.Timestamp<=?) AND
(itable.Application in ('1','2','3','4'))
GROUP BY itable.Timestamp, itable.Time
ORDER BY itable.Timestamp, itable.Time
and i get a data with an interval of 15 minutes like this :
Timestamp Time CallsOffered CallsAnswered CallsAnsweredAftThreshold CallsAnsweredDelay
6/1/2014 0:00 00:00 0 1 1 52
6/1/2014 0:15 00:15 3 1 1 23
6/1/2014 0:30 00:30 3 3 2 89
6/1/2014 0:45 00:45 0 0 0 0
6/1/2014 1:00 01:00 0 0 0 0
6/1/2014 1:15 01:15 4 1 1 12
6/1/2014 1:30 01:30 1 1 1 39
6/1/2014 1:45 01:45 0 0 0 0
6/1/2014 2:00 02:00 2 1 0 7
6/1/2014 2:15 02:15 1 1 1 80
6/1/2014 2:30 02:30 3 2 2 75
6/1/2014 2:45 02:45 0 0 0 0
6/1/2014 3:00 03:00 0 0 0 0
and i want to convert the interval from being 15 minutes to hourly interval
like this
2014-07-01 00:00:00.000
2014-07-01 01:00:00.000
2014-07-01 02:00:00.000
2014-07-01 03:00:00.000
2014-07-01 04:00:00.000
2014-07-01 05:00:00.000
2014-07-01 06:00:00.000
2014-07-01 07:00:00.000
2014-07-01 08:00:00.000
2014-07-01 09:00:00.000
2014-07-01 10:00:00.000
2014-07-01 11:00:00.000
2014-07-01 12:00:00.000
2014-07-01 13:00:00.000
2014-07-01 14:00:00.000
the query i came up with is :
select
timestamp = DATEADD(hour,datediff(hour,0,app.Timestamp),0),
Sum(app.CallsOffered)AS CallsOffered,
Sum(app.CallsAnswered)AS CallsAnswered,
Sum(app.CallsAnsweredAftThreshold)AS CallsAnsweredAftThreshold,
sum(CallsAnsweredDelay)AS CallsAnsweredDelay,
max(MaxCallsAnsDelay) as MaxCallsAnsDelay ,
max(app.MaxCallsAbandonedDelay)as MaxCallsAbandonedDelay
from tablename app
where Timestamp >='2014-7-1' AND timestamp<='2014-7-2' and
(app.Application in (
'1',
'2',
'3',
'4')
group by DATEADD(hour,datediff(hour,0,Timestamp),0)
order by Timestamp;
i get the result i want when i run in in Microsoft Sql server Managment studio
but it gives me a long error when i try running the same query in Microsoft Query in excel the error is like i cant start with timestamp
and that its giving me error for DATEADD ,DATEDIFF
so is there something i should change in my query or anything i can do to get an hourly count interval instead of 15 minutes count interval as ive shown
and thank you in advance