SQL Server 2008 - Grouping results into 5 minute intervals - sql-server-2008

Question

I currently have a SQL script that returns the results of data items that are processed into the database from imported files, however we are looking at getting a count of the number of items that come into the database broken into 5 minute intervals, for a defined day.
My existing script is as follows:
declare #date datetime
set #date = '2016-12-07 00:00:00.000
Select filename, IE.dateprocessingstarted
from tdii_inboundprocessed IE
inner join consignmentpf cpf
on ie.inboundfileprocessedid = cpf.inboundprocessedid
where 1=1 and (ie.dateprocessingstarted between `#date` and `dateadd(dd,1,#date)`
This returns the following:
FilenameDate ProcessingStarted
GOOD813546 2016-12-07 00:02:00
GOOD813546 2016-12-07 00:02:00
GOOD813546 2016-12-07 00:02:00
GOOD813546 2016-12-07 00:02:00
GOOD813546 2016-12-07 00:02:00
GOOD813546 2016-12-07 00:02:00
GOOD813554 2016-12-07 00:08:00
GOOD813554 2016-12-07 00:08:00
GOOD813554 2016-12-07 00:08:00
GOOD813554 2016-12-07 00:08:00
What I'd like to see is:
datetime numberoffiles
2016-12-07 00:05:00 6
2016-12-07 00:10:00 4
etc
the tdii_inboundprocessed table contains the details of files coming into the system, including the time we are interested in dateprocessingstarted) the consignmentpf table contains the details of items within a particular file and this is the number we are interested in getting a count of.
Thank you for any help

Answer 1

SELECT t.date ,
COUNT(*)
FROM ( SELECT DATEADD(MINUTE,
( ( DATEDIFF(MINUTE, #date,
IE.dateprocessingstarted) / 5 ) * 5 )
+ 5, #date) [date]
FROM #tdii_inboundprocessed IE
INNER JOIN consignmentpf cpf ON IE.inboundfileprocessedid = cpf.inboundprocessedid
WHERE 1 = 1
AND ( IE.dateprocessingstarted BETWEEN #date
AND DATEADD(dd, 1,
#date) )
) AS t
GROUP BY t.date;