This function returns the week of the given date as a number.
Date is the date to return the week number from
Return Type is a number representing the day on which the week starts
|1 or Omitted||Sunday|
|WeekNum(Today())||If this function is called on 10/18/2010 it will return 43 as the week number|
|WeekNum("10/18/2010",12)||This will return 42 as the date given falls on a Monday and the week is set to start on a Tuesday (12).|