One of the great things about Shirley Jackson's The Lottery is that we don't know when or where it takes place. From the opening lines we know the date and weather, but these are the only concrete details given in the story.
The morning of June 27th was clear and sunny, with the fresh warmth of a full-summer day; the flowers were blossoming profusely and the grass was richly green. The people of the village began to gather in the square, between the post office and the bank, around ten o'clock; in some towns there were so many people that the lottery took two days and had to be started on June 2th. but in this village, where there were only about three hundred people, the whole lottery took less than two hours, so it could begin at ten o'clock in the morning and still be through in time to allow the villagers to get home for noon dinner.
Readers contemplate why Jackson would intentionally leave these details of her setting out while giving so many other details. Most people believe it is because Jackson wants the reader to believe that the events that transpire on this beautiful summer day could happen in any town at any time. Realizing this, she warns the reader to avoid falling into traditions simply because they've always been done that way the same way the town has.