4.2.19 Time Zone Identifier

Basic Definition | Description| | Example

Basic Definition

Parameter Name
To specify the identifier for the time zone definition for a time component in the property value.

Format Definition

This property parameter is defined by the
following notation:

  tzidparam  = "TZID" "=" [tzidprefix] paramtext CRLF

  tzidprefix = "/"


The parameter MUST be specified on the "DTSTART", "DTEND", "DUE", "EXDATE" and "RDATE" properties when either a DATE- TIME or TIME value type is specified and when the value is not either a UTC or a "floating" time. Refer to the DATE-TIME or TIME value type definition for a description of UTC and "floating time" formats. This property parameter specifies a text value which uniquely identifies the "VTIMEZONE" calendar component to be used when evaluating the time portion of the property. The value of the TZID property parameter will be equal to the value of the TZID property for the matching time zone definition. An individual "VTIMEZONE" calendar component MUST be specified for each unique "TZID" parameter value specified in the iCalendar object.

The parameter MUST be specified on properties with a DATE-TIME value if the DATE-TIME is not either a UTC or a "floating" time.

The presence of the SOLIDUS character (US-ASCII decimal 47) as a prefix, indicates that this TZID represents a 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 Olson database [TZ]. The specification of globally unique time zone identifiers is not addressed by this document and is left for future study.

The following are examples of this property parameter:



The TZID property parameter MUST NOT be applied to DATE-TIME or TIME properties whose time values are specified in UTC.

The use of local time in a DATE-TIME or TIME value without the TZID property parameter is to be interpreted as a local time value, regardless of the existence of "VTIMEZONE" calendar components in the iCalendar object.

For more information see the sections on the data types DATE-TIME and TIME.


(No exmple provided)