Zulu Switching Calendars
These instructions will explain how to move an event from one calendar to another.This is a little different depending on how you've set up your multiple calendars...
Switching between two calendars based on the same table, but filtered using a filter field
An example of this might be changing an item's status when you have the calendar set to filter by a field called "status".
In FileMaker, of course, all you do to move an event from one calendar to another is change the contents of the field you're using as your FilterKey (status in this example).
iCal lets you do the same thing, but it's a little different. Edit the event in iCal and switch calendars: Zulu will switch the filter field to the filter value used in the new calendar. Sadly, this only works on the desktop version of iCal: on the iPhone and iPad you can't move an event from one calendar to another (though you can assign a calendar when you create the event).
Switching between two calendars based on different FileMaker Pro tables
When switching between two calendars based on different FileMaker Pro tables, the record being changed is marked as deleted in the table in which it originally resides, by placing a 1 in the "deleted" field. (Remember, you can have FileMaker Server run a script schedule to periodically find and delete records with a 1 in them this way.)
But, when the new record is created in your other FileMaker table, only those fields mapped on the event_mapping layout (the one you created in step 5 here) will be added to the new record: iCal doesn't know anything about the other fields in your table, and certainly doesn't know how to map them to the fields in your other table.
The newly created record will have its own unique FileMaker ID according to the auto-enter settings of your primary key field, but will have the same iCal UUID as the original record before it was moved to the new calendar.
Note that you don't really have a way to prevent your iCal uses from doing this (switching an item from one calendar to a totally unrelated calendar based on another table) and, as you can see, the results really aren't pretty. So you'll want to train your users not to do this.
Switching between a Zulu calendar and some other iCal calendar
You can drag an event from another iCal calendar into a Zulu calendar and the corresponding FileMaker Record will be created. If you drag an event from Zulu to another iCal Calendar, it appears to work, but the FileMaker record behind the Zulu calendar is not deleted, meaning that it will come back the next time iCal refreshes and it will appear you have two of the event: one in the new calendar you dragged to, one in Zulu. Switching calendars in Google Calendar
This does not work so well, and is one of the current limitations of our Google calendar synch. Changing an event's calendar causes the event to be tagged as "deleted" in FileMaker (marked with a "1" in the deleted field, not actually deleted) and an new event created for the new calendar: this is not ideal since much of the information in the original event is not carried over to the new one. While we plan to fox this soon, for now please instruct your users not to change an event's calendar in Google calendar.