Extract dates of a given day

[hmidi slim <hmidi.slim2@xxxxxxxxx>]

Hi,

I have a table availability: id (integer), product varchar(255), period (daterange)

I want to extract dates from a given period matching a given day.

E.g:  for the period from 01/04/2018 - 30/04/2018 and for day = Monday I want to get
02/04/2018
09/04/2018
16/04/2018
23/04/2018
30/04/2018

I want to make a query such as (the query doesn't work ) but I want to extract dates from daterange type:

select * from availability

where period @> '[2018-04-02, 2018-04-20]'

and extract(dow from period_date) = 1

How can I extract dates from daterange?