India has notified the Legal Metrology (Indian Standard Time) Rules, 2026, establishing Indian Standard Time (IST) as the common time reference for legal, administrative, commercial and other official purposes across the country. The rules were notified on 27 August 2026 and will come into force 180 days after their publication in the Official Gazette, giving government departments, businesses and institutions time to update their systems. The move is part of the government’s “One Nation, One Time” initiative and is aimed at ensuring accurate and consistent timekeeping across critical sectors such as banking and digital payments, telecommunications, railways, transportation, power systems, data networks and government services. Reliable and synchronized time stamps are particularly important for financial transactions, digital systems and cybersecurity, where even small timing differences can affect the coordination and tracking of activities.