HELP needed; table and query development

I ve posted this question a few days ago, is there somebody out there who can help me???

I have got a database with customer info and some extra fields 4 per day, 7 days per week.
So in general: id; cust info; mon_m_s; mon_m_e; etc.; timestamp.
field explenation:
mon_m_s = monday morning start
mon_m_e = monday morning end

The follwing question:
I want to log the default openingtimes in the main database above.
But I also want to log and search when a customer is closed or has extra openingtimes.

I thought to create two extra tables:
Extra Opening:
unique_id;ID (the link id form the main db); open_s(datetime);open_e(datetime).
Close dates:
unique_id; ID (the link id from the main db);
start_date(date);end_date(date).

Is this the way to go???
How do I query them, for example; what is open today?

john