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Property Name



This property specifies the text value that uniquely identifies the "VTIMEZONE" calendar component in the scope of an iCalendar object.

Value Type


Property Parameters

IANA and non-standard property parameters can be specified on this property.


This property MUST be specified in a "VTIMEZONE" calendar component.


This is the label by which a time zone calendar component is referenced by any iCalendar properties whose value type is either DATE-TIME or TIME and not intended to specify a UTC or a "floating" time. The presence of the SOLIDUS character as a prefix, indicates that this "TZID" represents an unique ID in a globally defined time zone registry (when such registry is defined).

Note: This document does not define a naming convention for time zone identifiers. Implementers may want to use the naming conventions defined in existing time zone specifications such as the public-domain TZ database [TZDB]. The specification of globally unique time zone identifiers is not addressed by this document and is left for future study.

Format Definition

This property is defined by the following notation:

 tzid       = "TZID" tzidpropparam ":" [tzidprefix] text CRLF

 tzidpropparam      = *(";" other-param)

 ;tzidprefix        = "/"
 ; Defined previously. Just listed here for reader convenience.


The following are examples of non-globally unique time zone identifiers:



The following is an example of a fictitious globally unique time zone identifier:


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