The calendar on the wall at the end of the store counter shows the month of May 1929.
When Wheezer pays for his 5c worth of candy, he gives Grandma a bogus coin known as "company scrip" (tokens issued to employees, typically by rural logging or mining companies, as a substitute for real money) could only be used in each company's store. Grandma lets him slide, and drops the token into a cash drawer with some scrip tokens of different denominations, buttons, metal washers and other worthless items. In the drawer, the right edge of a cigar store coupon - another form of scrip that could only be used in one kind of store - can be seen.