Hyderabad is 4.5-5.5 hours ahead of London. London uses GMT/BST while Hyderabad uses Indian Standard Time (IST, UTC+5:30). When it's 9:00 AM in London, it's 2:30 PM (BST) or 3:30 PM (GMT) in Hyderabad.
India does not observe daylight saving time, but the UK does. The difference is 4.5 hours during British Summer Time and 5.5 hours during GMT.
Best calling time: 4:00 AM - 12:00 PM London time. This corresponds to 9:30 AM - 5:30 PM in Hyderabad, covering Indian business hours.
Hyderabad is India's major tech hub, hosting offices of Microsoft, Google, Amazon, and many IT companies. The city is often called "Cyberabad" for its technology industry. Direct flights from London take about 10 hours.