Indian Standard Time (IST) (Geography)
Indian Standard Time (IST) (Geography)
Why In News:
The Department of Consumer Affairs notified the Legal Metrology (Indian Standard Time) Rules, 2026 on 27 August 2026.
About the Rules
The rules establish Indian Standard Time (IST) as the single mandatory reference time for legal, administrative, commercial and official purposes across India.
The rules will come into force 180 days after their publication in the Official Gazette, allowing institutions and businesses to synchronise their systems.
The initiative forms part of the “One Nation, One Time” programme, aimed at establishing a uniform and reliable national time reference.
NavIC and other approved Indian timing sources can be used for secure and accurate time dissemination and synchronisation.
Indian Standard Time (IST)
IST is UTC +5:30 and is based on the 82°30′ East longitude reference meridian.
The reference meridian passes near Mirzapur in Uttar Pradesh.
India follows one standard time zone despite its wide east–west geographical extent.
India does not observe Daylight Saving Time (DST).
CSIR–National Physical Laboratory (NPL), New Delhi is the custodian of Indian Standard Time and maintains national time and frequency standards.
Coordinated Universal Time (UTC) serves as the international reference against which IST and other national times are expressed.
NavIC and Time Dissemination
NavIC (Navigation with Indian Constellation) is India's indigenous regional satellite navigation system, developed and operated by ISRO.
NavIC provides three major services—Position, Navigation and Timing (PNT)—making it useful for navigation as well as the precise synchronisation of clocks and networks.
It provides coverage over India and the surrounding region, extending approximately 1,500 km beyond India's mainland.
NavIC uses a constellation of geostationary (GEO) and geosynchronous (GSO) satellites, which enables continuous regional coverage and reliable timing signals.
For time dissemination, NavIC can transmit highly accurate timing signals that can synchronise systems such as telecommunications, financial networks, power grids and critical infrastructure with Indian Standard Time.
Under the One Nation, One Time initiative, NavIC can therefore serve as an indigenous source for secure and reliable IST synchronisation, reducing dependence on foreign satellite-navigation systems for critical timing requirements.