Machine-readable rule source
Exact offsets and transition rows come from the IANA Time Zone Database as exposed by the deployed runtime. IANA publishes tzdb releases when governments change civil-time rules.
Check IANA Time Zone DatabaseIANA timezone
Asia/Kolkata.
ISTUTC+05:30Standard time
Asia/Kolkata is the IANA timezone for India, currently at UTC+05:30 (IST). It does not observe daylight saving time; the offset stays the same year-round. The zone covers 4 cities listed below, with live clocks updating every second.
Offset, DST behavior, and city coverage are refreshed from the live timezone dataset during the page revalidation window.
Current time in IST
--:--:--Asia/Kolkata · UTC+05:30
Abbreviation
IST
UTC Offset
UTC+05:30
DST Status
Standard Time
Country
India
Timezone planning depth
What Asia/Kolkata is useful for
A timezone page should do more than define an offset. These notes connect the zone to city clocks, DST behavior, converters, and adjacent country planning pages.
Zone identity
Asia/Kolkata is rendered as IST at UTC+05:30 for India. The IANA zone ID is the stable key; the abbreviation is only the short display label.
DST behavior
Asia/Kolkata has no scheduled offset transitions in the next 12 months. The displayed UTC+05:30 is stable year-round, which makes long-horizon scheduling, billing, and report-window math straightforward.
City coverage
4 indexable cities sit in this zone after locale and crawl-safety filters, with Mumbai, Delhi, Bengaluru, and Hyderabad among the examples shown.
Conversion handoff
The fastest jumps from IST are the curated converter pairs to CET, JST, and AEST.
Adjacent planning context
The most useful next steps from this timezone page are holiday calendars, airport-country planning, and city clocks. Those links keep the zone page connected to real user tasks rather than stopping at an offset definition.
Single-abbreviation behavior
Asia/Kolkata resolves to a single abbreviation, GMT+5:30, in the next 12 months. That makes the abbreviation usable as a short display label, but the IANA zone is still the canonical key for storage and conversion math.
Offset stability
Asia/Kolkata spends about 365 days at UTC+05:30 across the forward 12-month window, which makes it stable across the entire window. The remaining time is split across the other offsets listed in the year-of-DST card.
Peer zones at the same offset
Other IANA zones currently aligned at UTC+05:30 include Asia/Colombo. Same-offset peers can drift apart later in the year if their DST rules differ, so a peer match today is not a permanent equivalence.
Country roster
Asia/Kolkata is used as the primary clock anchor for India. The roster is derived from country-zone mappings, so it reflects which jurisdictions adopt this IANA zone rather than which countries happen to share its current offset.
Timezone abbreviations can be ambiguous. The IANA zone name is the canonical key used for clocks, city pages, and conversion math.
Source-change watch
When timezone policy changes
CSIR-NPL Indian Standard Time
Indian Standard Time is UTC(NPLI)+05:30; current IANA data has no seasonal DST transition for Kolkata.
Check policy sourceYear-round offset behavior
Asia/Kolkata across the next 12 months
Asia/Kolkata has no scheduled offset transitions in the next 12 months. The displayed UTC+05:30 (GMT+5:30) stays stable across the window. That makes long-horizon scheduling, billing, and report-window math straightforward — meeting times do not need to track DST boundaries here.
Coverage reference
What Asia/Kolkata covers
Country roster
Common abbreviations
Abbreviations rotate with each DST transition — anchor calendar entries to the IANA zone, not an abbreviation.
Peer zones at UTC+05:30 right now
Same-offset peers can drift apart later in the year if their DST rules differ; today's offset match is not a permanent equivalence.
Convert IST Time
Cities in IST
FAQ
- What is the current UTC offset for Asia/Kolkata?
- Asia/Kolkata is currently at UTC+05:30 (GMT+5:30). The page revalidates weekly, but live clocks on this page tick from the IANA zone in real time.
- Does Asia/Kolkata observe daylight saving time in 2027?
- No. Asia/Kolkata has no scheduled offset transitions in the next 12 months and currently stays at UTC+05:30 year-round.
- Which cities use Asia/Kolkata?
- Asia/Kolkata is the canonical clock for cities including Mumbai, Delhi, Bengaluru, Hyderabad. The page lists 4 indexable cities in this zone after locale and crawl-safety filters.
- What abbreviations does Asia/Kolkata use?
- Asia/Kolkata resolves to IST year-round in the next 12 months.
- Why does India use Asia/Kolkata?
- India is mapped to Asia/Kolkata as one of its IANA zones in the country-zone catalog. The IANA zone records each jurisdiction's historical offset and DST rule changes; Asia/Kolkata stores the rules used by India (ISO IN).
Related timezone pages
Most timezone-reference visits naturally branch into a country page, abbreviation page, or converter workflow.