timeZoneId property
a string containing the ID of the time zone, such as "America/Los_Angeles" or "Australia/Sydney". These IDs are defined by Unicode Common Locale Data Repository (CLDR) project, and currently available in file timezone.xml. When a timezone has several IDs, the canonical one is returned. In xml responses, this is the first alias of each timezone. For example, "Asia/Calcutta" is returned, not "Asia/Kolkata".
Implementation
@BuiltValueField(wireName: r'timeZoneId')
String? get timeZoneId;