The Jabber protocols have long included a method for discovering the time at another entity's location. This method makes use of the 'jabber:iq:time' namespace and has been documented variously in Internet-Drafts and elsewhere. Because this protocol is not required by &rfc2779;, the 'jabber:iq:time' namespace was removed from &xmppim;. This JEP fills the void for canonical documentation.

The 'jabber:iq:time' namespace provides a standard way for Jabber entities to exchange information about the local time (e.g., to "ping" another entity or check network latency). The information is communicated in a request/response pair using an &IQ; element that contains a &QUERY; scoped by the 'jabber:iq:time' namespace. The following children of the &QUERY; element are allowed in an IQ result:

• <utc/> -- The time (in UTC) according to the responding entity. The format SHOULD be "CCYYMMDDThh:mm:ss" (see below). This element is REQUIRED in an IQ result.
• <tz/> -- The time zone in which the responding entity is located. This can be either a three-letter acronym or the full natural-language name of the timezone. A list of time zone names and abbreviations is located at <http://www.timeanddate.com/library/abbreviations/timezones/>. This element is OPTIONAL in an IQ result.
• <display/> -- The time in a human-readable format. This element is OPTIONAL in an IQ result.

The standard error conditions described in &jep0086; apply (e.g., service unavailable if the entity does not support the namespace).

&jep0082; defines the lexical representation of dates, times, and datetimes in Jabber protocols. Unfortunately, the 'jabber:iq:time' namespace predates that definition, and uses a datetime format ("CCYYMMDDThh:mm:ss") that is inconsistent with JEP-0082 and &w3xmlschema2;. Because a large base of deployed software uses the old format, this JEP specifies that applications using 'jabber:iq:time' SHOULD use the old format, not the format defined in JEP-0082. In addition, note well that the datetime provided in the <utc/> element is explicitly UTC and therefore SHOULD NOT include the ending 'Z' character required by &iso8601;.

There are no security features or concerns related to this proposal.

This JEP requires no interaction with &IANA;.

The 'jabber:iq:time' namespace is registered in the protocol namespaces registry maintained by the ®ISTRAR;.