Ordering a date_part() query ...

I have a query that looks like:

SELECT ( date_part('month', stat_period) || '/' ||         date_part('day', stat_period)   || '/' ||
date_part('year',stat_period)  || ' ' ||        date_part('hour', stat_period)  || ':00:00' ) as "Summary - by
 
Day/Hour",      sum(impressions) as impressions, sum(click_thru) as click_thru FROM banner_count
GROUP BY "Summary - by Day/Hour";


Works great, except that the output looks like:

Summary - by Day/Hour|impressions|click_thru
---------------------+-----------+----------
1/17/2000 23:00:00   |         63|         1
1/18/2000 0:00:00    |        151|         0
1/18/2000 10:00:00   |        348|         4
1/18/2000 11:00:00   |        804|         1
1/18/2000 12:00:00   |        180|         1
1/18/2000 1:00:00    |         89|         0
1/18/2000 2:00:00    |        112|         0
1/18/2000 3:00:00    |        178|         0
1/18/2000 4:00:00    |        184|         0
1/18/2000 5:00:00    |        133|         0
1/18/2000 6:00:00    |        119|         0
1/18/2000 7:00:00    |        148|         0
1/18/2000 8:00:00    |        224|         0
1/18/2000 9:00:00    |        272|         0

Notice the 10/11/12/etc hour stats come before the 1am stats?

So its sorting okay on the date, but I need to get it to d it on the time
as well..

I'm still playing with it, but if someone can suggest a means of doing
this, I'm all ears :)

Thanks...

Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
Systems Administrator @ hub.org 
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org