BEGIN:VEVENT
DESCRIPTION
 :An example where the days generated makes a difference because of
 WKST:
DTSTART
 ;TZID=US-Eastern
 :19970805T090000
RRULE
 :FREQ=WEEKLY;COUNT=4;INTERVAL=2;BYDAY=TU,SU
END:VEVENT

BEGIN:VEVENT
DESCRIPTION
 :An example where the days generated makes a difference because of
 WKST. Changing only WKST from MO to SU yields different results...
DTSTART
 ;TZID=US-Eastern
 :19970805T090000
RRULE
 :FREQ=WEEKLY;COUNT=4;INTERVAL=2;BYDAY=TU,SU
END:VEVENT

BEGIN:VEVENT
DESCRIPTION
 :The 3rd instance into the month of one of Tuesday\, Wednesday or
 Thursday\, for the next 6 months:
DTSTART
 ;TZID=US-Eastern
 :19970904T090000
RRULE
 :FREQ=MONTHLY;COUNT=6;INTERVAL=1;BYDAY=TU,WE,TH;BYSETPOS=3
END:VEVENT

BEGIN:VEVENT
DESCRIPTION
 :The 2nd to last weekday of the month:
DTSTART
 ;TZID=US-Eastern
 :19970929T090000
RRULE
 :FREQ=MONTHLY;COUNT=10;INTERVAL=1;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-2
END:VEVENT