Greenwich mean time is ––––––––––– the Indian Standard Time (IST).

5.5 hours ahead 12 hours ahead 4.5 hours behind 5.5 hours behind

5.5 hours behind

Indian Standard Time is 5 hours and 30 minutes ahead of Greenwich Mean Time. The earth revolves from west to east. So, those places lying to the east of Greenwich will be ahead Greenwich time and those to the west will be behind Greenwich time. The Indian Standard Meridian is located 82 and 1/2∘ east of the Prime Meridian. thus, the Indian Standard Time is 5 and a half hours ahead of the Greenwich Mean Time (GMT).