India mandates Indian Standard Time as sole official reference by 2027

The Indian government has notified the Legal Metrology (Indian Standard Time) Rules, 2026, establishing Indian Standard Time (IST) as the mandatory single time reference for all legal, administrative, commercial, and public services across the country.

Notified on August 27, 2026, the rules will come into effect approximately 180 days after their publication in the official gazette, which is expected around March 2027. This transition period is intended to allow government departments, private companies, and technical institutions to synchronize their servers, networks, and digital infrastructures with the new standard.

The initiative aims to eliminate discrepancies in digital transactions and reduce reliance on foreign time sources. Key sectors affected by this standardization include banking and finance (specifically for microsecond-accurate digital payments and stock exchanges), transportation (railways and aviation), telecommunications (5G networks and data centers), and power grid management. Under the Legal Metrology Act, using time sources other than IST for official purposes may be subject to penalties, with specific exceptions for astronomy and scientific research.