Centre mandates IST as single time reference across India, gives 180 days for compliance

The government has notified rules making Indian Standard Time (IST) the single reference for legal, administrative, commercial and other official purposes across the country, with stakeholders being given 180 days to align their systems with the new requirement.

The Legal Metrology (Indian Standard Time) Rules, 2026 were notified by the Ministry of Consumer Affairs, the nodal ministry, on August 27. They will come into force 180 days after their publication in the official gazette.

The transition period is intended to give government departments, businesses and other institutions time to make the necessary technical changes and ensure compliance.

The move comes at a time when digital and technology-driven systems are increasingly dependent on accurate and synchronised timestamps. These include banking and digital payments, telecommunications, railways, power grids and computer networks.

The ministry said discrepancies between different time sources currently in use could affect the coordination and recording of such activities, making a uniform national time standard necessary.

According to the government, the common reference will facilitate accurate time-stamping of banking and digital payment transactions, coordination across railways, airports and other transport systems, and reliable functioning of telecommunications and internet networks.

It will also support precise time-keeping in power systems, maintenance of government and legal records, and coordination of emergency and other time-sensitive services, the ministry said.

Push for Indian timing sources

A key component of the new rules is reducing dependence on foreign satellite-based timing sources, which are currently used by several critical systems.

The government is developing infrastructure to disseminate accurate IST through Indian institutions and legal metrology laboratories.

The rules also permit the use of NavIC, India's indigenous satellite navigation system, along with other approved Indian timing sources, for secure and reliable dissemination of time.

White Rabbit technology trial

The new rules are part of the government's 'One Nation, One Time' initiative.

As part of the programme, the Ministry of Consumer Affairs in July 2026 commissioned a White Rabbit Technology-based IST Dissemination Demonstration Network at the Regional Reference Standard Laboratory (RRSL) in Bengaluru.

The pilot demonstrated the dissemination of IST across multiple sectors, including banking, telecommunications, power, transportation and digital governance.

In another demonstration, the ministry, in collaboration with CSIR-National Physical Laboratory, Isro, Sebi, the National Stock Exchange (NSE) and BSNL, showcased secure transmission of IST between RRSL Bengaluru and NSE Chennai.

The ministry said the 180-day transition period would enable stakeholders to examine their existing systems, undertake required technical upgrades and prepare for full implementation before the rules come into effect.

The initiative is aimed at establishing a secure and reliable Indian timing infrastructure and ensuring that critical systems across the country operate on a common and synchronised time reference.