A point based model of the Gregorian Calendar

Time is an important aspect of all real world entities; temporal information is crucial in many computer-based applications. The Smalltalk community does not have a good model of the time domain. Smalltalk-80 and its commercial implementations provide only the classes Date and Time to model time domain entities. Squeak augmented the model with the abstractions Timespan, Year, Month and Week. These models fall short when complex situations of the time domain have to be programmed, forcing the programmers to create their own and repetitive solutions. In this paper, we present a model of the Gregorian Calendar based on a metaphor that maps time entities into points of lines, each line with its own resolution. The model addresses a great amount of functionality and reifies almost all the Gregorian Calendar entities. It allows programmers to design and program time related issues better than current time domain implementations, and in a more natural way.