·
Rules
notified: The
Central Government has notified the Legal
Metrology (Indian Standard Time) Rules, 2026 under Section 52 of the Legal Metrology
Act, 2009, through G.S.R.
761(E) dated 27 August 2026.
·
Effective
date: The
Rules will come into force 180
days after publication in the Official Gazette.
·
Purpose: Establish a national framework for the generation, maintenance, dissemination,
synchronisation, traceability and use of Indian Standard Time (IST).
·
Official
time standard: IST
is the official time scale for civil,
commercial and legal purposes
in India. It is maintained by CSIR–National
Physical Laboratory (NPLI)
and derived from UTC(NPLI) with a 5-hour
30-minute offset.
·
Mandatory
time reference: IST
will be the standard reference for commerce,
transport, public administration, legal contracts and financial operations.
·
Other
time references prohibited:
Entities cannot use, display or record time references other than IST, except
for specified circumstances such as scientific
research, navigation and astronomy,
subject to the prescribed conditions and prior approval.
·
Government
and public institutions:
Government offices and public institutions must synchronise time-dependent
applications and public displays with IST through authorised timing sources.
·
Critical
sectors covered:
Telecommunications, financial services, energy and data centres must
synchronise time-dependent systems with IST using authorised sources traceable
to UTC(NPLI).
·
Authorised
timing sources: These
include NPLI,
Regional Reference Standards Laboratories (RRSLs), NavIC-based
timing devices, the National Informatics Centre (NIC) and other authorised sources.
·
NTP/PTP
protocols:
Authorised timing sources will provide time dissemination through standard
protocols such as Network
Time Protocol (NTP) and Precision Time Protocol (PTP).
·
Cybersecurity
requirements:
Time-synchronisation systems must incorporate robust cybersecurity measures
against jamming,
spoofing and cyber-attacks.
·
Redundancy
mandated:
Critical infrastructure sectors—including defence, power grids, utilities, telecom,
banking and finance, transportation, broadcasting and data centres—must maintain redundant
time-synchronisation systems.
·
NavIC integration: Critical systems must incorporate NavIC or another authorised timing source as a timing reference. GNSS-based timing
devices must receive at least one timing reference directly from NavIC or an authorised source.
·
Business
continuity:
Organisations must maintain mechanisms to ensure uninterrupted timing services
during reference-source failures, including the use of stable atomic clocks or authorised timing sources.
·
Audits
and enforcement:
Periodic audits will verify compliance, IST traceability and availability. The Legal Metrology Division will oversee enforcement.
·
Penalties: Violations of the Rules will attract
penalties under the Legal
Metrology Act, 2009, with
the Director, Legal Metrology or an authorised officer empowered to conduct
inquiries and impose penalties.
Key
takeaway: The
Rules create a legally backed single,
traceable Indian time standard,
with particular importance for financial
systems, telecom, energy, data centres and other critical infrastructure, while strengthening the role of NPLI and NavIC and requiring resilience against timing
disruptions and cyber-attacks.