Wednesday, June 29, 2011

Time Zones in India

My brother and his wife had been to Sikkim for holidays. My sister-in-law was telling me that the sun rises at about 4:45 am over there. I was awestruck about this fact at first. But later on, after checking a few things, I realized that the same sun rises in Mumbai at 6:05 am and the difference in the sunrise time is because we have the same time zone throughout the country. Ideally Sikkim's local time should be 1 hour 20 minutes ahead of Mumbai's local time such that the sunrise time would be the same in both these cities.

Now consider this weird example. If you look at the geographical locations of Guwahati, Dhaka and Kolkata, the sun first rises in Guwahati, then in Dhaka and later on in Kolkata. However, surprisingly, the sunrise time in these 3 cities is 4:34 am, 5:15 am and 4:55 am respectively. Now the question is how can the sun rise in Dhaka at a time later than that of Guwahati? Again, blame it on the time zones. Guwahati and Kolkata follow the Indian Standard Time (IST) whereas Dhaka follows the Bangladesh Standard Time which is 30 minutes ahead of IST. So, if Dhaka was in India (like old times i.e. before independence) and it would have followed IST, the sunrise time over there would have been 4:45 am which falls in line with the sunrise times of the other two cities!

One final example can be the city of Omsk in Russia (73°22′E) which is located almost on the same longitude as Mumbai (72°49′33″E). The sunrise time in Omsk is 5:31 am as compared to Mumbai's sunrise time of 6:05 am - different sunrise time on the same longitude!!

Furthermore, the Russian capital Moscow's local time is 3 hours behind that of Omsk. In this case, two cities from the same country have different time zones. Now consider the distance between these two cities. It's 2,235 kms, which is almost the same as the distance of 2,385 kms between Mumbai and Gangtok, the capital city of Sikkim! So, I personally think that India should also follow different time zones for distant cities. I don't know the other repercussions of having different time zones in India, but at least it will help our countrymen to follow the exact local time. The sun will rise at the normal time throughout the country. I guess everything else including wake up time, office timings, sleeping time, etc. will be normal too!

Useful Links:
1. Time Zone Converter: