How to use daterange type?

Hi,

I'm using postgresql 9.2.

I'm trying to figure out how can I use daterange type in my database
that is supposed to be a school calendar.

I did the followings at the postgresql command prompt:

create database schoolcalendar;
create table semester_1 ( schooldays daterange );
insert into semester_1 values ( '[2012-09-01, 2012-12-24]' );

So how can I use this table further eg. to get dates of the school days
but without Saturdays and Sundays?

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Regards from Pal