Writing a function to select data only on weekdays in PostgreSQL

Question

I am working on a Postgres 8.3 database. A query I use is meant to only select rows that are included in weekdays. Right now I have do do this by hand like in the example below but I want to transfer this to some funciotn where I can specefic the start and end dates and get the same logic to apply as below. That is

How can you create a function whose input is a start and end date and the result of the function will be to select all rows only included in the weekdays of the data sets (I want to exlude every staurday and sunday as in the where clause condition below)?

create table filter_tbl as
select *
from base_tbl  where
(start_Time >= '2012-11-5' and start_Time < '2012-11-10')
or (start_time >= '2012-11-12' and start_time < '2012-11-17')
or (start_time >= '2012-11-19' and start_time < '2012-11-24')
or (start_time >= '2012-11-26' and start_time < '2012-12-01')
or (start_time >= '2012-12-03' and start_time < '2012-12-07')
or (start_time >= '2012-12-10' and start_time < '2012-12-14')
or (start_time >= '2012-12-17' and start_time < '2012-12-21')
or (start_time >= '2012-12-24' and start_time < '2012-12-28')
or (start_time >= '2012-12-31' and start_time < '2013-01-04')
or (start_time >= '2013-01-07' and start_time < '2013-01-11')
or (start_time >= '2013-01-14' and start_time < '2013-01-18')
or (start_time >= '2013-01-21' and start_time < '2013-01-25')
or (start_time >= '2013-01-28' and start_time < '2013-02-02')
or (start_time >= '2013-02-04' and start_time < '2013-02-09')
or (start_time >= '2013-02-11' and start_time < '2013-02-16')
or (start_time >= '2013-02-18' and start_time < '2013-02-23')
or (start_time >= '2013-02-25' and start_time < '2013-03-02')
or (start_time >= '2013-03-04' and start_time < '2013-03-09')
or (start_time >= '2013-03-11' and start_time < '2013-03-16');

Answer 1

The following should return the day of the week.

date_part('dow', Date);

With the default settings 0 is Sunday and 6 is Saturday