/* $DOC$
   $NAME$
      ft_Week()
   $CATEGORY$
      Date/Time
   $ONELINER$
      Return calendar or fiscal week data
   $SYNTAX$
      ft_Week( [ <dGivenDate> ], [ <nWeekNum> ] ) -> aDateinfo
   $ARGUMENTS$
      <dGivenDate> is any valid date in any date format.  Defaults
      to current system date if not supplied.

      <nWeekNum> is a number from 1 to 53 signifying a week.
      Defaults to current week if not supplied.
   $RETURNS$
      A three element array containing the following data:

         aDateInfo[ 1 ] - The year and week as a character string "YYYYWW"
         aDateInfo[ 2 ] - The beginning date of the week
         aDateInfo[ 3 ] - The ending date of the week
   $DESCRIPTION$
      ft_Week() returns an array containing data about the week
      containing the given date.

      Normally the return data will be based on a year beginning
      on January 1st with weeks beginning on Sunday.

      The beginning of year date and/or beginning of week day can be
      changed by using ft_DateCnfg(), which will affect all subsequent
      calls to ft_Week() until another call to ft_DateCnfg().

      The beginning of year date and beginning of week day may be reset
      to January 1 and Sunday by calling ft_DateCnfg() with no
      parameters.
   $EXAMPLES$
      // get info about week containing 1990-09-15
      aDateInfo := ft_Week( hb_SToD( "19900915" ) )
      ? aDateInfo[ 1 ]   //  199037       (37th week)
      ? aDateInfo[ 2 ]   //  1990-09-09   beginning of week 37
      ? aDateInfo[ 3 ]   //  1990-09-15   end of week 37

      // get info about week 25 in year containing 1990-09-15
      aDateInfo := ft_Week( hb_SToD( "19900915" ), 25 )
      ? aDateInfo[ 1 ]   //  199025
      ? aDateInfo[ 2 ]   //  1990-06-17   beginning of week 25
      ? aDateInfo[ 3 ]   //  1990-06-23   end of week 25

      // get info about week 25 in current Year( 1991 )
      aDateInfo := ft_Week( , 25 )
      ? aDateInfo[ 1 ]   //  199025
      ? aDateInfo[ 2 ]   //  1991-06-16   beginning of week 25
      ? aDateInfo[ 3 ]   //  1991-06-22   end of week 25
   $SEEALSO$
      ft_DateCnfg(), ft_Month(), ft_Qtr(), ft_Year(), ft_DayToBoW()
   $END$
 */