Christmas Grocery hours
In Australia, shops are required to remain closed on Christmas day, December 25. (They are also closed Good Friday, but that is irrelevant to this problem).
The grocery store that I go to is open from 10am to 8pm every weekday, and 8am to 10pm every weekend.
From December 22 to 28 in 2013 (inclusive), how many hours is the grocery shop open for?