Network Identity and Time Zone (NITZ)
is a mechanism for provisioning local
time
Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...
and date,
time zone
A time zone is an area which observes a uniform standard time for legal, Commerce, commercial and social purposes. Time zones tend to follow the boundaries between Country, countries and their Administrative division, subdivisions instead of ...
and
daylight saving time
Daylight saving time (DST), also referred to as daylight savings time, daylight time (Daylight saving time in the United States, United States and Daylight saving time in Canada, Canada), or summer time (British Summer Time, United Kingdom, ...
(DST) offset, as well as
network provider identity information, to
mobile devices
A mobile device or handheld device is a computer small enough to hold and operate in hand. Mobile devices are typically battery-powered and possess a flat-panel display and one or more built-in input devices, such as a touchscreen or keypad. Mod ...
via a wireless network.
History
NITZ has been an optional part of the official
GSM
The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile phones and Mobile broadband modem, mobile broadba ...
standard since phase 2+ release 96.
NITZ is often used to automatically update the system clock of mobile phones.
In terms of standards and other timing or network access protocols such as
NTP or
CDMA2000
CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatib ...
, the quality and enforcement of NITZ is weak. This standard allows the network to "transfer its current identity, universal time, DST and LTZ"
but each is optional, and support across
RAN
RAN may refer to:
* Radio access network, a part of a mobile telecommunication system
* Rainforest Action Network
* Ran (gene) (RAs-related Nuclear protein), also known as GTP-binding nuclear protein Ran, a protein that in humans is encoded by t ...
vendor and operator varies. This presents a problem for device manufacturers, who are required to maintain a complex time zone database, rather than rely on the network operator. Additionally, unlike
3GPP2
The 3rd Generation Partnership Project 2 (3GPP2) was a collaboration between telecommunications associations to make a globally applicable third generation (3G) mobile phone system specification within the scope of the ITU's IMT-2000 project. ...
, which transmits
GPS
The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide geol ...
-sourced, millisecond resolution time via the sync channel, for NITZ, the "accuracy of the time information is in the order of minutes".
The optional nature of the delivery mechanism results in issues for users in regions that don't practice daylight saving but which share a time zone with a region that does.
Most modern handsets have their own internal time zone software and will automatically perform a daylight saving advance.
Because the NITZ delivery is not usually periodic but dependent on the handset crossing radio network boundaries, these handsets can be displaying incorrect time for many hours or even days before a NITZ update arrives and corrects them.
Carriers supporting NITZ
Initial list derived from ref:
{, class="wikitable sortable"
, -
! scope="col" , Country
! scope="col" , Carrier
! scope="col" , NITZ available since
! scope="col" class="unsortable" , Notes
, -
, , , Optus , , Y , ,
, -
, , , Telstra , , Y , ,
, -
, , , Three , , Y , ,
, -
, , , Nar , , 2014 , ,
, -
, , , Rogers , , Y , ,
, -
, , , SaskTel , , Y , ,
, -
, , , China Mobile , , Y , ,
, -
, , , A1 , , Y , ,
, -
, , , Telefónica O2 , , Y , ,
, -
, , , T-Mobile , , Y , ,
, -
, , , Vodafone , , Y , ,
, -
, , , Bouygues Telecom , , Y , ,
, -
, , , Free , , Y , ,
, -
, , , Orange , , Y , ,
, -
, , , SFR , , , ,
, -
, , , DNA , , Y , ,
, -
, , , Sonera , , Y (pre-2000) , ,
, -
, , , Telefónica O2 , , 2009 , , ref
, -
, , , PCCW , , Y , ,
, -
, , , SmarTone , , Y , ,
, -
, , , T-Mobile , , Y , ,
, -
, , , Wind , , Y , ,
, -
, , , U Mobile , , Y , ,
, -
, , , Telcel , , Y , ,
, -
, , , KPN , , Y , ,
, -
, , , Vodafone , , Y , ,
, -
, , , 2degrees , , Y , ,
, -
, , , Spark New Zealand , , Y , ,
, -
, , , Vodafone , , Y , ,
, -
, , , MTN , , Y , ,
, -
, , , T-Mobile , , Y , , 2G and 3G
, -
, , , P4 Play , , Y , , 3G only
, -
, , , Plus (telecommunications Poland) , , Y , , 2G and 3G
, -
, , , Aero2 , , Y , , 2G and 3G
, -
, , , Zapp , , Y , ,
, -
, , , Salt , , Y , , 3G only
, -
, , , MTS , , Y , ,
, -
, , , Telia , , Y , ,
, -
, , , Telenor , , Y , ,
, -
, , , Sunrise , , Y , ,
, -
, , , Swisscom , , Y , ,
, -
, , , Salt , , Y , ,
, -
, , , Turkcell , , Y , ,
, -
, , , Vodafone , , Y , ,
, -
, , , Chunghwa Telecom , , Y , ,
, -
, , , Telefónica O2 , , Y , ,
, -
, , , Vodafone , , Y , , ref
, -
, , , AT&T , , Y , ,
, -
, , , T-Mobile , , Y , ,
, -
, , ,
, , - , ,
, -
, , , Türk Telekom , , - , , ref
References
GSM standard
Mobile phones