Not Legal Advice: In Oklahoma, liquor stores can only be open from 10 a.m. to 9 p.m., and low-point beer can not be sold at grocery stores or convenience stores between 2 a.m. and 6 a.m.
It is illegal in the state of Oklahoma to sell packaged liquor for consumption "off-premises" on Sundays and holidays: Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day.
As of 2007, liquor stores can now be open on election days.
The rules for restaurants & bars are different than those above in the state of Oklahoma, as the consumption is "on premises." For these establishments, individual counties get to decide whether to allow "by the drink" alcohol purchases, but alcohol can not be sold between 2 a.m. and 7 a.m.
Know more about Oklahoma liquor laws from this link: http://okc.about.com/od/foodanddrink/p/okliquorlaws.htm.