Typically, people mark time by watching the clock. The day is divided into hours and minutes and we plan accordingly. For the learner who is deafblind, the abstract concept of time needs to be made more concrete. Time is marked by the sequence of events and the routines that occur throughout the day. In the absence of a calendar system, the learner may be forever stuck in the present. The calendar system allows for discussion about things before they happen and after they are finished.

Each individual calendar box represents a block of time in which a certain activity occurs. With consistent use, the calendar becomes a concrete way to show the passage of time (e.g. what is finished, what will happen later, what order things will occur).

Calendar systems also offer opportunities to develop about time concepts and vocabulary such as finished, wait, later, morning, afternoon, yesterday, today, tomorrow, first, second, third, next.