Before continuing with this article, it would be best to become familiar with Appointment Instances, as described in the article Creating Appointments and Instances.
To begin modifying an Appointment and its instances, its details must first be viewed, as described under the subsection Viewing an Appointment in the Navigating the Calendar article. If you have permissions to modify the Appointment, one or more Modify buttons will appear on the page.
Modification Types
The type of modifications that are available for an Appointment will depend on the instance's place in the Appointment's series of instances.
Modify
If it is a non-recurring Appointment, then only a single Modify button will appear on the page. This button will take you to a page where you can update the options, all of which belong to the single Appointment-instance pair. This is the most straightforward of the modifications.
Modify This Instance
In cases where the Appointment has more than one instance, the option to modify This Instance will be available. Since all the instances share a majority of its details through the Appointment, the way the system allows for this uniquely modified Appointment to exist is by duplicating it, making the modifications to the newly duplicated Appointment, and attaching the instance to the duplicate instead of the original. This is depicted in the diagram below, where a user chooses to modify an instance of their Appointment.
This means that (going by the diagram above) if the user views the details of Instance 1, 3, or 4, and chooses to Modify All Instances (see below), Instance 2 will not be affected.
This also means that Instance 2 becomes a non-recurring Appointment, as it is now a single Appointment-instance pair. Viewing the details page of Instance 2 will only show a single Modify button.
Modify This And X Subsequent Instances
In cases where the Appointment has more than one instance, and the instance being viewed is not the last one, the option to modify This And X Subsequent Instances will be available, where X denotes the number of instances that share the Appointment, and takes place later than the currently viewed instance.
Similarly to modifying This Instance, this option will duplicate the Appointment, make modifications to the newly duplicated Appointment, and attach the currently viewed and subsequent instances to the duplicate Appointment. This is depicted in the diagram below, where the user chooses this modification type when viewing Instance 2.
This means that (going by the diagram above) Instance 1 becomes part of a single Appointment-instance pair with the original Appointment, and viewing its details will only show the single Modify option.
This also means that Instances 2, 3, and 4 share a single Appointment, so viewing the details of any one of those instances will show the availability of one or more of the mass modification types.
Modify All X Instances
In all cases where the Appointment has more than one instance, the option to modify All X Instances will be available, where X denotes the total number of instances that share the Appointment.
Since this modification type involves making a change uniformly across all of the instances, no duplication is involved (unlike the previous two modification types). The change is made to the single Appointment, which all of the existing attached instances continue to share.