I have this VTIMEZONE block

BEGIN:VTIMEZONE              
TZID:Asia/Dubai              
BEGIN:STANDARD               
DTSTART:20000101T000000      
RRULE:FREQ=YEARLY;BYMONTH=1  
TZNAME:+04                   
TZOFFSETFROM:+0400           
TZOFFSETTO:+0400             
END:STANDARD                 
END:VTIMEZONE                

Because the RRULE block is missing the BYDAY statement, outlook does is not able to parse this. I know that this is compliant code, but anyway, adding BYDAY does not hurt in this case.

Changing from
RRULE:FREQ=YEARLY;BYMONTH=1
to
RRULE:FREQ=YEARLY;BYDAY=1;BYMONTH=1
does the jobs.

This applies to places that do not have any clock change during the year.

I'm using vobject 0.9.6