Perpetual calendars like this one gained popularity in the mid-20th century as functional desk accessories and souvenirs. They were often made of metal or plastic and featured flip mechanisms to display the date. These calendars were commonly adorned with images of landmarks or tourist attractions, making them popular mementos for travelers.

This particular calendar showcases iconic Chicago landmarks such as the Museum of Science and Industry and the John Hancock Center (misspelled as 'COCK CENTER' on the calendar). The inclusion of the Sears Tower (now Willis Tower), labeled as 'World's Tallest Building,' helps to pinpoint the era in which this calendar was produced. These calendars evoke a sense of nostalgia and represent a time when physical souvenirs were cherished keepsakes.