$begin(calendar,level)

$begin(calendar,level) returns the start of the period in which today falls according to the defined calendar

The following example returns the start of the current week according to the Manufacturing calendar:

$begin(Manufacturing,Week)

This function is equivalent to $begin(calendar,level,$today). The level parameter corresponds to a level in the default hierarchy of the calendar dimension. This function is a generalization of the $week(calendar), $month(calendar), and $quarter(calendar) functions.