Formatting results

Here is my table:

table tst:

id | date | num
---+---------------------+----
1 | 2005-09-22 14:37:21 | 5
2 | 2005-09-22 10:22:33 | 3
3 | 2005-09-21 10:22:34 | 3
4 | 2005-09-14 10:33:21 | 5
5 | 2005-09-22 17:34:22 | 5

Here is my query:

SELECT num,date_trunc('day',date),COUNT(*) FROM tst
WHERE date_trunc('day',date)<'2005-09-23' AND date_trunc('day',date)>'2005-09-13' GROUP BY num,date_trunc('day',date)

I realize that my date ranges use the entire table in this example. In real life my table has data outside the selected range.

Here are my results:

num| date_trunc | count
---+---------------------+----
3 | 2005-09-21 00:00:00 | 1
3 | 2005-09-22 00:00:00 | 1
5 | 2005-09-14 00:00:00 | 1
5 | 2005-09-22 00:00:00 | 2

Which is what I would expect. What I would like is the output formatted like this:

num| 2005-09-14 | 2005-09-21 | 2005-09-22
---+------------+------------+-----------
3 | 0 | 1 | 1
5 | 1 | 0 | 2

Is there a SQL way to do this? I'd rather not use a stored procedure, and I would like to be able to do this on databases besides postgres. (I am current using postgres, so that is my primary focus. I just like to be general if possible)

Thanks.

Todd