The Montessori materials all share certain characteristics. They are beautiful and elegant by design, isolating a single concept and offering some child-centered control of error. For concrete concepts, like quantities or colors, this is fairly straight-forward. For abstract concepts, like time, for example, this can be more complicated. We match that by offering some lessons to embody the experience of the concept like carrying the globe around a candle the same number of times the earth has orbited the sun since the child's birth to show the passage of time, or comparing timelines of different phenomena on the same scale to demonstrate how the passage of time is longer or shorter. But we also offer lessons to introduce the ways in which we represent these abstracts in our day-to-day life, like vocabulary lessons. The Perpetual Calendar is one such lesson.
The Perpetual Calendar is a simple wooden frame with space to place tags for the month, year, days of the week and numbers for each day. It can be adjusted to match any month, and is accompanied by control cards specific to the month and year we are currently in or to the month and year of the child's birth or of some other event. Children with more proficiency in counting from 1 to 31 can place the numbered days in their appropriate slot, building a calendar that matches the one they may see handing in their classroom or on a planner. They can practice placing the names in the week in order from Sunday to Saturday, labeling the calendar for the appropriate month or placing out the digits in the current year. Through this repeated practice, children learn the norms for calendar-keeping appropriate to our culture, and can compare those experiences with calendars across time and in other cultures. Calendars are, after all, a cultural artifact. That's why you'll find this lesson not on the Math or Language shelves or even Practical Life, but nestled in the Cultural curriculum, surrounded by timelines like the Life Cycle of a Butterfly or the Timeline of Life, or by cycle materials, like the Phases of the Moon or the Water Cycle. Like the other Cultural materials, the Perpetual Calendar teaches children a little more about what it means to live in this culture, at this time, in this moment in history.