1. Legal Metrology (Indian Standard Time) Rules, 2026 Notified
- The Legal Metrology (Indian Standard Time) Rules, 2026 make IST the common, legally recognised and traceable time reference.
- They fall under the Ministry of Consumer Affairs and take effect 180 days after Gazette publication.
- CSIR-National Physical Laboratory is the primary authority, supported by ISRO and five Regional Reference Standard Laboratories.
- Time is disseminated via NTP, PTP, NavIC and White Rabbit optical fibre.