RRULE BYDAY with BYSETPOS is not work.

[신동민]

Hello.

I need to get "Monthly First Monday Repeat". 

expected result)

RRULE:FREQ=MONTHLY;UNTIL=20161225T150000Z;INTERVAL=1;BYDAY=1MO

0 = "2016-05-02T03:00:00.000Z"
1 = "2016-06-06T03:00:00.000Z"
2 = "2016-07-04T03:00:00.000Z"
3 = "2016-08-01T03:00:00.000Z"
4 = "2016-09-05T03:00:00.000Z"
5 = "2016-10-03T03:00:00.000Z"
6 = "2016-11-07T03:00:00.000Z"
7 = "2016-12-05T03:00:00.000Z"

not expected result)

RRULE:FREQ=MONTHLY;UNTIL=20161225T150000Z;INTERVAL=1;BYDAY=MO;BYSETPOS=1

0 = "2016-05-02T03:00:00.000Z"
1 = "2016-06-05T15:00:00.000Z"
2 = "2016-07-03T15:00:00.000Z"
3 = "2016-07-31T15:00:00.000Z"
4 = "2016-09-04T15:00:00.000Z"
5 = "2016-10-02T15:00:00.000Z"
6 = "2016-11-06T15:00:00.000Z"
7 = "2016-12-04T15:00:00.000Z"

I ask how to solve it using BYSETPOS?

[Mike Samuel]

Why are you using datetimes instead of just dates as in
RRULE:FREQ=MONTHLY;UNTIL=20161225;INTERVAL=1;BYDAY=1MO ?

What is your DTSTART? And what timezone is it in?