Timezone Data Distribution Service
charter-ietf-tzdist-00-02
Document | Proposed charter | Timezone Data Distribution Service WG (tzdist) Snapshot | |
---|---|---|---|
Title | Timezone Data Distribution Service | ||
Last updated | 2014-07-03 | ||
State | Start Chartering/Rechartering (Internal Steering Group/IAB Review) | ||
WG | State | Proposed | |
IESG | Responsible AD | Barry Leiba | |
Charter edit AD | Barry Leiba | ||
Send notices to | cyrus@daboo.name |
Timezone Data Distribution Service (tzdist)
Timezone data is a critical element of computer systems and devices that
make use of local time. In particular, it is critical to any calendaring
and scheduling system, such as iCalendar (RFC 5545). Daylight saving
time rules, which affect local UTC offsets, can change - sometimes at
very short notice (just a few days) - as those rules are typically
defined by political processes. Currently, there is no efficient, fast
way to ensure that timezone data is updated in a timely and reliable
manner on devices that need it. Timezone changes are often delivered as
operating system updates, and are thus tied to release schedules that
can trail the actual timezone changes by a significant period of time. A
service is needed that can provide timely, reliable updates.
One added benefit of such a service for iCalendar is the ability for
calendaring clients and servers to agree on common, standard definitions
of timezone data, removing the need to pass timezone data directly "by
value" in iCalendar data. By allowing clients and servers to use
timezones "by reference" significant network bandwidth and storage
savings can be achieved.
This working group will:
-
Define a timezone data distribution protocol that allows for
efficient, timely updates of timezone data to be delivered to clients.
This protocol must scale to vast numbers of clients, such as the
potential "internet of things" devices, as well as to today's desktop
computers and servers. -
Define an extension to CalDAV (RFC 4791) to allow clients and servers
to use timezones "by reference" to improve the efficiency of the overall
protocol.
The working group will use the following drafts as initial input for its
work:
draft-douglass-timezone-service-11
draft-daboo-caldav-timezone-ref-01
The working group will work under the following parameters:
-
The timezone data distribution protocol will initially be targeted at
iCalendar-based clients, but should be flexible enough to deliver
timezone data in other formats. -
The timezone data will be based on the IANA Time Zone Database
(http://www.iana.org/time-zones) but must be able to include any source
of timezone data. -
The timezone data distribution protocol should also offer an API to
allow thin clients to easily make use of timezone data by querying for
UTC offsets, offloading the sometimes complex work of expanding
recurrence rules to the service. This API should be extensible to
support other types of timezone operations in the future. -
The timezone data distribution protocol will use current security
protocols to protect the integrity and confidentiality of what is
distributed. Even public timezone data can represent a significant
privacy exposure when it is associated with the user or endpoint that
is retrieving it.
The following are Out of scope for the working group:
-
Any changes to the IANA timezone database process or infrastructure,
as documented in RFC 6557, other than recommendations for possible
security enhancements. -
The naming process for timezone identifiers. The working group can
consider adding a mechanism, such as a "namespace" prefix, to
differentiate different timezone sources, but the nature of the timezone
identifiers used will be controlled by the sources themselves. -
Lookup protocols or APIs to map a location to a timezone.