After how many days from Gazette publication do the Legal Metrology (Indian Standard Time) Rules, 2026 come into force?

The correct answer is 180 days. The Rules were notified by the Department of Consumer Affairs on 27 August 2026 and published in the Official Gazette on 29 August 2026, and the release states that they take effect 180 days from the date of that publication. The gap gives telecommunications networks, financial systems, power grids, transport operators, data centres and government information systems time to synchronise with a traceable source before the legal obligation begins. Options A, B and D are not mentioned anywhere in the release and are offered only as plausible commencement periods, since Indian rules are often brought into force after thirty or ninety days. Note the two dates carefully as well, because notification and Gazette publication fall two days apart, and the 180-day count runs from publication rather than from the day the Rules were signed.