Kolkata to Tokyo Time

Live IST ↔ JST time converter · West Bengal, India → Japan

Kolkata IST (Indian Standard Time) · UTC+05:30
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West Bengal, India
3.5h ahead of IST
UTC+9
Tokyo JST (Japan Standard Time) · UTC+9
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Japan

24-Hour Overlap Timeline

✅ Overlap: 9:00 AM–2:00 PM in Kolkata · 1:00 PM–6:00 PM in Tokyo (5h window)
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UTC →
🇮🇳 Kolkata UTC+5:30 5a 6a 7a 8a 9a 10a 11a 12p 1p 2p 3p 4p 5p 6p 7p 8p 9p 10p 11p 12a 1a 2a 3a 4a
🇯🇵 Tokyo UTC+9 9a 10a 11a 12p 1p 2p 3p 4p 5p 6p 7p 8p 9p 10p 11p 12a 1a 2a 3a 4a 5a 6a 7a 8a
Both working Working Off hours Sleeping Now

IST (Indian Standard Time) to Tokyo (JST (Japan Standard Time)) Conversion Table

All 24 hours of the day · based on JST (Japan Standard Time).
✅ Both in business hours 🔵 India office hours only 🟢 Tokyo office hours only

IST (Indian Standard Time) — Kolkata Tokyo — JST Working hours
12:00 AM IST (Indian Standard Time) 3:30 AM JST
1:00 AM IST (Indian Standard Time) 4:30 AM JST
2:00 AM IST (Indian Standard Time) 5:30 AM JST
3:00 AM IST (Indian Standard Time) 6:30 AM JST
4:00 AM IST (Indian Standard Time) 7:30 AM JST
5:00 AM IST (Indian Standard Time) 8:30 AM JST
6:00 AM IST (Indian Standard Time) 9:30 AM JST 🟢 JST only
7:00 AM IST (Indian Standard Time) 10:30 AM JST 🟢 JST only
8:00 AM IST (Indian Standard Time) 11:30 AM JST 🟢 JST only
9:00 AM IST (Indian Standard Time) 12:30 PM JST ✅ overlap
10:00 AM IST (Indian Standard Time) 1:30 PM JST ✅ overlap
11:00 AM IST (Indian Standard Time) 2:30 PM JST ✅ overlap
12:00 PM IST (Indian Standard Time) 3:30 PM JST ✅ overlap
1:00 PM IST (Indian Standard Time) 4:30 PM JST ✅ overlap
2:00 PM IST (Indian Standard Time) 5:30 PM JST 🔵 India only
3:00 PM IST (Indian Standard Time) 6:30 PM JST 🔵 India only
4:00 PM IST (Indian Standard Time) 7:30 PM JST 🔵 India only
5:00 PM IST (Indian Standard Time) 8:30 PM JST 🔵 India only
6:00 PM IST (Indian Standard Time) 9:30 PM JST
7:00 PM IST (Indian Standard Time) 10:30 PM JST
8:00 PM IST (Indian Standard Time) 11:30 PM JST
9:00 PM IST (Indian Standard Time) 12:30 AM JST +1 day
10:00 PM IST (Indian Standard Time) 1:30 AM JST +1 day
11:00 PM IST (Indian Standard Time) 2:30 AM JST +1 day
🇮🇳 Travel Guide

Explore Kolkata — Top Attractions & Travel Guide

Discover top attractions, local tips and hidden gems in Kolkata on india-guide.in — India's curated travel destination guide.

Explore Kolkata on india-guide.in →

Best Time to Call Tokyo from Kolkata

Business Hours Overlap 9:00 AM – 1:30 PM IST

Both Kolkata and Tokyo are in standard business hours simultaneously during this window. Schedule meetings, investor calls, or client demos in this slot for maximum availability.

Morning India call
9:00 AM IST
12:30 PM JST
Midday call
12:00 PM IST
3:30 PM JST
End of India day
6:00 PM IST
9:30 PM JST
🇮🇳

Kolkata, India

Time zone: IST (UTC+05:30) — fixed, no DST
State: West Bengal

Kolkata is eastern India's commercial and cultural hub, and serves as the gateway to north-east India and Bangladesh. The city's jute, tea, and coal trade built British India. Today it houses the Calcutta Stock Exchange and is a growing IT destination. Kolkata's intellectual and literary tradition makes it India's cultural capital. It is the closest major Indian city to South-East Asia, with strong historic trade ties.

  • Gateway to North-East India and Bangladesh
  • Calcutta Stock Exchange — India's second oldest
  • India's dominant jute, tea, and coal trading centre historically
  • Closest major India city to South-East Asian markets
🇮🇳 Explore Kolkata attractions on india-guide.in →
🇯🇵

Tokyo, Japan

Time zone: JST (UTC+9, no DST)
Region: East Asia

Tokyo is the world's largest metropolitan area and home to the Tokyo Stock Exchange, the world's third-largest by capitalisation. Major Japanese corporations — Toyota, Sony, SoftBank — all have significant India investments. SoftBank's Vision Fund, headquartered in Tokyo, has deployed tens of billions of dollars into Indian startups including Flipkart, Ola, and Paytm.

  • No DST — always 3.5h ahead of IST
  • World's largest metro by population
  • SoftBank Vision Fund — India's largest tech investor
  • Mumbai–Ahmedabad bullet train: Japan–India partnership
India connections: SoftBank Vision Fund — India's top startup investor. Toyota, Honda, Suzuki all manufacture in India. Japan–India infrastructure projects (Mumbai-Ahmedabad bullet train). Direct Air India flights from Delhi & Mumbai.

Frequently Asked Questions

What is the time difference between Kolkata and Tokyo?
Tokyo is always 3.5h ahead of IST year-round. Japan does not observe daylight saving time.
What is 9 AM IST in Tokyo?
9:00 AM IST (Kolkata) = 12:30 PM JST in Tokyo.
What is the best time to schedule a meeting between Kolkata and Tokyo?
The optimal meeting window is 9:00 AM–1:30 PM IST when both Kolkata and Tokyo offices are open. Book in this window to avoid after-hours calls.
Does India observe daylight saving time (DST)?
No. India (IST, UTC+5:30) does not observe daylight saving time and has not done so since 1945. Indian Standard Time is fixed year-round. This means that when Tokyo also does not change, so the Kolkata–Tokyo offset is perfectly stable all year.
Why is India on a half-hour timezone (UTC+5:30)?
India's UTC+5:30 offset was established in 1905 as a compromise between the time zones of Bombay (UTC+4:52) and Calcutta (UTC+5:54) when India unified under British rule. Several countries use half-hour or quarter-hour offsets — including Nepal (UTC+5:45), Iran (UTC+3:30), and parts of Australia (UTC+9:30) — to better align solar noon with clock noon across their territory.