Ministry of Consumer Affairs issues Legal Metrology (Indian Standard Time) Rules, 2026

The Ministry of Consumer Affairs, Food and Public Distribution (“Ministry”) has issued the Legal Metrology (Indian Standard Time) Rules, 2026 (“Rules”) under the Legal Metrology Act, 2009 (“Act”). The Rules provide the framework for the generation, maintenance, dissemination, synchronisation, traceability and use of Indian Standard Time (“IST”) in accordance with the provisions of the Act with a view to ensure uniform adoption and synchronisation of IST across the country and promoting accuracy, reliability, traceability, operational efficiency, resilience and security in commerce, industry, critical infrastructure.

The Rules will come into effect after 180 days from the date of publication in the Official Gazette, i.e. on 23^rd February, 2027.

Key Highlights:

1. An entity must not use, display or record any time reference other than IST for all purposes. If any law in force / orders / directions / guidelines permit for display of time of foreign time zones with clear labelling alongside IST, alternate time scales may be used for scientific research, navigation or astronomy with prior approval.

• Entities operating within critical sectors, including telecommunications, financial services, energy and data centers, must ensure that time-dependent systems are synchronised to IST using an authorised time source traceable to *UTC (NPLI).

• The time-synchronisation systems shall incorporate robust cybersecurity measures to safeguard against malicious attacks. The end-entity must employ a redundant time synchronisation system to ensure continuous time traceable to UTC (NPLI) or IST.

• All entities and organisations must implement and maintain a comprehensive contingency plan to mitigate potential disruptions, including jamming, spoofing and cyber-attacks, affecting their time-synchronisation systems.

• To safeguard national and economic security, all the critical infrastructure sectors including defence, power grids, utilities, telecommunications, banking and finance, transportation, enterprises, broadcasting, data centers, etc. must utilise a redundant time synchronization system and such system must incorporate the **NavIC or one or more authorised timing sources as a timing reference in addition to other authorised timing source.

• All entities and organisations must integrate one or more authorised timing sources into their timing infrastructure to mitigate disruptions and ensure continuity of network operations and mission-critical services.

Source: Ministry of Consumer Affairs, Food and Public Distribution