Org-mode version 9.2.2, Emacs 26.1, Windows 10
To reproduce:
Create a file "Test.org", with only one entry:
----------------------------------------------------------------------------
* TODO Do this on the second Monday every month
SCHEDULED: <%%(diary-float t 1 2) 19:00-20:30>
:PROPERTIES:
:ID: 5eb2262f-d7a4-4c10-8765-e1906a1cf276
:END:
------------------------------------------------------------------------------
Run this in the buffer of this above file:
M-x org-icalendar-export-to-ics
Check the output file "Test.ics", and you will see something like
below, which obviously is wrong (I highlighted the wrong part).
BTW: regular org-agenda still works correctly with this entry
(the TODO shows up correct at the right date)
-------------------------------------------------------------------------------
BEGIN:VCALENDAR
VERSION:2.0
X-WR-CALNAME:Test
PRODID:-////Emacs with Org mode//EN
X-WR-TIMEZONE:America/New_York
X-WR-CALDESC:
CALSCALE:GREGORIAN
BEGIN:VTODO
UID:TODO-5eb2262f-d7a4-4c10-8765-e1906a1cf276
DTSTAMP:20190326T141906Z
DTSTART:20190326T101900
SUMMARY:Do this on the second Monday every month
CATEGORIES:Test
SEQUENCE:1
PRIORITY:13
STATUS:NEEDS-ACTION
END:VTODO
END:VCALENDAR
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