Why is there a time difference of about 5 hours between India and London?

The time difference of approximately 5 hours between India and London is due to the Earth’s rotation and the establishment of time zones worldwide. Here’s a detailed explanation:

The Earth’s Rotation and Time Zones

• The Earth rotates 360 degrees in 24 hours, meaning it rotates 15 degrees every hour.
• To standardize time globally, the Earth is divided into 24 time zones, each covering 15 degrees of longitude.
• The time at a location depends on its longitudinal position relative to the Prime Meridian (0° longitude), which passes through Greenwich, London.

The Earth’s Rotation and Time Zones

• The Earth rotates 360 degrees in 24 hours, meaning it rotates 15 degrees every hour.
• To standardize time globally, the Earth is divided into 24 time zones, each covering 15 degrees of longitude.
• The time at a location depends on its longitudinal position relative to the Prime Meridian (0° longitude), which passes through Greenwich, London.

Historical Factors

• India’s Standard Time Zone: India adopted 82.5° E longitude as the standard meridian in 1906 for a unified national time.
• Daylight Saving in the UK: Unlike India, the UK adjusts its clocks for daylight saving to make better use of daylight during the summer months.

Table of Time Difference Between India and London

Season	London Time Zone	India Time Zone	Time Difference
Standard Time (Nov–Mar)	GMT	GMT +5:30	5 hours 30 minutes
Daylight Saving Time (Mar–Oct)	BST (GMT +1)	GMT +5:30	4 hours 30 minutes

Why Is This Important?

Understanding time differences is crucial for:

• Business and communication: Scheduling meetings between India and the UK.
• Travel planning: Managing jet lag and adjusting itineraries.
• Cultural awareness: Respecting time zones for global collaboration.

By knowing how time zones work, you can efficiently coordinate activities across different parts of the world.