If I'm understanding you correctly this should get you what you need; however I could be going in the completely wrong direction.
Create a formula:
totext(hour({table.timefield}))
&
totext(minute({table.timefield}))
&
totext({table.numberfield})
This gives each set of records a unique ID based on the time and the number, if you now group by this formula you can do a count of records.
ie using your example data set the result would be as follows;
group; time; number; count;
93020 4
9:30 20
9:30 20
9:30 20
9:30 20
103050 4
10:30 50
10:30 50
10:30 50
10:30 50
103020 4
10:30 20
10:30 20
10:30 20
10:30 20
Regards,
Ryan.
Edited by rkrowland - 12 Apr 2012 at 12:51am