I am working on something that requires me to count how many consecutive hours an evernt has occured over the last half year...
Is there anyone that has an idea that could help me?

The list consists of dates like:

07/07/2011 19
07/07/2011 20
07/07/2011 21
07/08/2011 07
07/08/2011 08
07/11/2011 07
07/18/2011 05
07/18/2011 06
07/18/2011 07
07/18/2011 08
07/21/2011 07
07/26/2011 07
07/26/2011 08
07/26/2011 09
07/26/2011 10
07/26/2011 11
07/26/2011 12
07/26/2011 13
07/28/2011 09
07/28/2011 12
07/29/2011 09
07/29/2011 10
07/29/2011 12
08/15/2011 08
08/16/2011 10
08/16/2011 11
08/16/2011 12
08/21/2011 12
09/11/2011 08
09/25/2011 11
10/05/2011 08
10/05/2011 09
10/07/2011 11
10/10/2011 09
10/10/2011 12
11/03/2011 05
11/03/2011 06
11/13/2011 08
11/18/2011 05
11/18/2011 06
11/18/2011 07
12/01/2011 13
12/03/2011 08
12/12/2011 06

ideally I want this summary at the end of a list, if possible.

16, 1 Hour Periods
4, 2 Hour Periods
3, 3 Hour Periods
1, 4 Hour Period
1, 7 Hour Period

Please let me know if you would like any more details of clarification, I will gladdly supply anything for help.