Returns the number of days from the beginning of the week to the specified date.
The DayNumber_Of_Week function provides improved performance compared to using the Sys_Calendar.Calendar system view to obtain similar results.
This statement is a Teradata extension to the ANSI SQL:2011 standard.
The result is an INTEGER value between 1 and 7, representing the day of the week, where the first day of the week = 1 and the last day of the week = 7. The first day of the week is defined by the business calendar the session is using. For example, in the ISO calendar, Monday = 1 and in the Teradata business calendar Monday = 2.