How does the WEEKDAY function categorize days in SAS?

The WEEKDAY function in SAS returns the day of the week as an integer ranging from 1 to 7, where 1 corresponds to Sunday and 7 corresponds to Saturday. This means that when using the WEEKDAY function, the output values are defined such that Sunday is considered the first day of the week, represented by the number 1. Consequently, the days follow in this order: Monday is 2, Tuesday is 3, and so forth, up to Saturday, which is represented by 7.

Understanding this categorization is essential for anyone manipulating date data within SAS because it allows for consistent and accurate analysis that relies on day-of-the-week calculations. This function is particularly useful in applications such as time series analysis or scheduling where the identification of specific days of the week is required.