GMT to IST Time Converter (London to Mumbai / Bengaluru)
Convert GMT (Greenwich Mean Time, London) to IST (India Standard Time, Mumbai / Bengaluru) instantly. View live clocks, 24-hour comparison table, best meeting overlap hours, and developer code snippets.
Interactive Hour Converter (GMT → IST)
Drag slider to test any hour24-Hour GMT to IST Time Conversion Table
Side-by-side hourly reference with business hours overlap indicators.
| GMT (London) | 24h | IST (Mumbai / Bengaluru) | 24h | Status in IST |
|---|---|---|---|---|
| 12:00 AM | 00:00 | 4:30 AM | 04:30 | Sleeping |
| 1:00 AM | 01:00 | 5:30 AM | 05:30 | Sleeping |
| 2:00 AM | 02:00 | 6:30 AM | 06:30 | Sleeping |
| 3:00 AM | 03:00 | 7:30 AM | 07:30 | Awake / Flex |
| 4:00 AM | 04:00 | 8:30 AM | 08:30 | Awake / Flex |
| 5:00 AM | 05:00 | 9:30 AM | 09:30 | Work Hours |
| 6:00 AM | 06:00 | 10:30 AM | 10:30 | Work Hours |
| 7:00 AM | 07:00 | 11:30 AM | 11:30 | Work Hours |
| 8:00 AM | 08:00 | 12:30 PM | 12:30 | Work Hours |
| 9:00 AM | 09:00 | 1:30 PM | 13:30 | Work Hours★ Best Meeting Overlap |
| 10:00 AM | 10:00 | 2:30 PM | 14:30 | Work Hours★ Best Meeting Overlap |
| 11:00 AM | 11:00 | 3:30 PM | 15:30 | Work Hours★ Best Meeting Overlap |
| 12:00 PM | 12:00 | 4:30 PM | 16:30 | Work Hours★ Best Meeting Overlap |
| 1:00 PM | 13:00 | 5:30 PM | 17:30 | Work Hours★ Best Meeting Overlap |
| 2:00 PM | 14:00 | 6:30 PM | 18:30 | Awake / Flex |
| 3:00 PM | 15:00 | 7:30 PM | 19:30 | Awake / Flex |
| 4:00 PM | 16:00 | 8:30 PM | 20:30 | Awake / Flex |
| 5:00 PM | 17:00 | 9:30 PM | 21:30 | Awake / Flex |
| 6:00 PM | 18:00 | 10:30 PM | 22:30 | Awake / Flex |
| 7:00 PM | 19:00 | 11:30 PM | 23:30 | Sleeping |
| 8:00 PM | 20:00 | 12:30 AM | 00:30 | Sleeping |
| 9:00 PM | 21:00 | 1:30 AM | 01:30 | Sleeping |
| 10:00 PM | 22:00 | 2:30 AM | 02:30 | Sleeping |
| 11:00 PM | 23:00 | 3:30 AM | 03:30 | Sleeping |
Developer Code Snippets (GMT to IST)
// Convert current time from GMT (Europe/London) to IST (Asia/Kolkata)
const now = new Date();
const inIST = new Intl.DateTimeFormat('en-US', {
timeZone: 'Asia/Kolkata',
dateStyle: 'medium',
timeStyle: 'long'
}).format(now);
console.log(inIST);# Python 3.9+ using standard zoneinfo
from datetime import datetime
from zoneinfo import ZoneInfo
dt_gmt = datetime.now(ZoneInfo("Europe/London"))
dt_ist = dt_gmt.astimezone(ZoneInfo("Asia/Kolkata"))
print(f"GMT: {dt_gmt.strftime('%Y-%m-%d %H:%M %Z')}")
print(f"IST: {dt_ist.strftime('%Y-%m-%d %H:%M %Z')}")Frequently Asked Questions (GMT → IST)
How do I convert GMT to IST?
GMT (Greenwich Mean Time) uses the IANA timezone identifier Europe/London (standard offset +00:00), while IST (India Standard Time) uses Asia/Kolkata (standard offset +05:30). Use the interactive slider or the 24-hour table above to convert any hour accurately with automatic Daylight Saving Time (DST) adjustment.
What are the best meeting hours between London and Mumbai / Bengaluru?
Check the rows highlighted with "Best Meeting Overlap" in the 24-hour table above, where both GMT and IST fall within standard 9:00 AM – 5:00 PM working hours.
Does GMT to IST account for Daylight Saving Time (DST)?
Yes. Castov uses the browser's native IANA tzdb engine (Europe/London and Asia/Kolkata), which automatically applies official Daylight Saving Time transitions.