Oracle's explanation about the special problem for Oracle Connector for Outlook

Outlook with OCFO creates 2 types of meetings. Single instance meetings and Recurring meetings.

When a single instance (i.e. NOT recurring) meeting is created, it is Outlook itself (not OCFO) that computes the UTC time. Outlook gets its timezone information from Windows definitions. If the Windows definition is not up to date, the UTC value will be incorrectly computed (even if the timezone definitions are correct on the calendar server), and conversely, if the MS definitions are correct, it doesn't matter if the Oracle timezone definitions are correct or incorrect, the UTC value will be stored correctly.

When a recurring meeting is created, Outlook passes a recurrence rule to OCFO, and OCFO passes the rule plus the applicable timezone definition to the calendar server which expands and calculates UTC values (in this case even if the MS timezones are not up to date, if the timezone rule from Oracle was correct, the recurrence will be correct).

Currently, Microsoft only supports a single definition of a timezone (unlike Oracle that can support multiple definitions for different years). This restricts them to altering their definitions shortly before the rule comes into effect. In fact, the first timezone patch was made available by MS on Nov 18, 2006. Their patches can be found at these links.

http://support.microsoft.com/kb/931836

http://support.microsoft.com/kb/928388/

The final piece to the problem. The Oracle Calendar Server does not store which client created the meeting nor the timezone (and the timezone definition) it was created with. We recognized this as a weakness and plan to address it in our next major release.

Stated more clearly, because of the potential mismatch of timezone definitions between MS and Oracle, it is impossible for Oracle to provide a universal and error free "correction tool" for adjusting (the current) calendar data in Oracle Collaboration Suite Calendar.