Walmart is open every day, but is closed once a year. This means that the only time that Walmart stores are closed is during Christmas day. If you are planning on visiting any Walmart store near you, the store is open from 06 in the morning and closes at exactly 11 in the evening. However, if you are planning on buying something for Christmas, make sure you do it before December 25 because you are just going to waste your time and gas only to find the store closed.
There was an instance when Walmart stores in Canada were open 24/7 last Christmas 2011, but unfortunately for people living in the United States, Christmas Day is the only major holiday that Walmart stores are closed.