Centre makes IST common time reference across India

The Government has notified the Legal Metrology (Indian Standard Time) Rules, 2026, mandating Indian Standard Time (IST) as the single reference for legal, administrative, commercial and other official purposes across the country.

The nodal consumer affairs ministry notified the rules on August 27, but they will come into force 180 days after their publication in the official gazette, giving government departments, businesses, and institutions time to align their systems. The move comes amid growing reliance on digital and technology-based systems — from banking and payments to telecommunications, railways, power grids and computer networks — that depend on accurate and synchronised timestamps.

The ministry said inconsistencies between different time sources currently in use could affect the coordination and recording of such activities, prompting the push for a uniform national time standard. The common time reference is expected to support accurate time-stamping of banking and digital payment transactions, coordination among railways, airports and other transport systems, reliable functioning of telecommunication and internet networks, precise time-keeping in power systems, upkeep of government and legal records, and coordination of emergency and other time-critical services, the ministry said in a statement.

A key feature of the rules is the emphasis on reducing dependence on foreign satellite-based time sources, which several critical systems currently rely on. The Government is building infrastructure to disseminate accurate IST through Indian institutions and legal metrology laboratories. The rules also enable the use of NavIC, India’s indigenous satellite navigation system, along with other approved Indian timing sources, for secure and reliable time dissemination.

As part of the ‘One Nation, One Time’ initiative, the ministry in July 2026 commissioned a White Rabbit Technology-based IST Dissemination Demonstration Network at the Regional Reference Standard Laboratory (RRSL) in Bengaluru.  The pilot has shown how IST can be

disseminated across sectors, such as banking, telecommunications, power, transportation, and digital governance. In a related demonstration, the ministry, in collaboration with CSIR-National Physical Laboratory, ISRO, SEBI, the National Stock Exchange (NSE) and BSNL, showed secure transmission of IST between RRSL Bengaluru and NSE Chennai.

The ministry said the 180-day transition period would allow stakeholders to review existing systems, carry out necessary technical upgrades, and prepare for full implementation before the Rules take effect.