I'm not much of a drinker but I do enjoy a cold beer on occasion and like to keep a box of Red Wine in the refrigerator (just to keep my cholesterol in check)... All too often I find myself at Tesco buying groceries and pick up a fresh "box-o-wine", proceed to the check out register only to be told that alcohol sales are not allowed at this particular time of day! How frustrating... The alcohol sale hours make no sense to me and I never seem to remember the rules.
Days and Times Alcohol can be bought in Thailand
You can buy alcohol between 1100 & 1400, and again between 1700 & midnight seven days per week.
There are other sales restrictions which include all Buddhist holidays, election days as well as other days as directed by the Thai Government.
This being said I have routinely found that small local stores more often than not will sell to you any time of day but they are either paying off the right police officer or risking a 10,000 baht fine and six months in prison...
Most bars and restaurants will sell you drinks for consumption within their establishment at any time that they are open.
Please remember to drink responsibly and DO NOT DRINK AND DRIVE! It's not worth risking your life or the lives of others just to "have a good time"!
One other word of caution is that it is not a good idea of taking "selfies" with your bottle of Chang or Leo and posting them on Social Media. That could land you in jail here in Thailand...