What is the natural time zone of Singapore ?
I have been living in Singapore for nearly 8 years now. I started going around the asean region as tourist a few years ago and started noticing that there were multiple time zones in the region. I am inquisitive by nature, and therefore began asking why so many time zones ?
Actually, I got this question every since I came to Singapore. In Hinduism, the religion I follow, everyday we have inauspicious times called in the Tamil language as “Ragukalam” and “Emakandam”. In India, the country I was born in, the earliest inauspicious time start at 6:00 AM and extend for 90 minutes. However, I noticed in Singapore this always start at 7:00 AM. In fact, the sun also rises at 7 AM. I asked a local Hindu temple, only to be told that it depends on the longitude and latitude of countries around the globe and some complex calculations. I wasn’t really satisfied with the reply, but the priest is not a scientist either to know the facts 
My first tourist trip was to Malaysia’s Langkawi island and they followed the same time zone as Singapore, GMT+8. Then, I went to Thailand and found that they were 1 hour behind us, GMT+7. Not surprising, Thailand is geographically west of Singapore. Then, recently I went to Bintan island, Indonesia. They were also 1 hour behind us at GMT+7. I wondered why when they are geographically just as Singapore or a little east of Singapore. Very recently, I traveled to Siem Reap, Cambodia and to my surprise they were also at GMT+7, a hour behind Singapore.
This last trip, made me conclude that it was Singapore which was not in its natural time zone. I started searching for an answer why? is it supposed to be a Daylight Saving Time (DST) and if so why it is not published as DST. Operating systems in its time zone settings don’t show Singapore time as using DST. So why ?
I asked Google, the oracle of the internet, and it promptly gave me an academic answer that to from National University of Singapore (NUS).
Quote from that page “The short answer is that West Malaysia follows the time zone for East Malaysia, and that Singapore follows West Malaysia.” If you are not from the region, you should know that west Malaysia is west of Singapore and East Malaysia is to the east of Singapore. This will help you to visualize the picture in your mind.
The long answer by the author Helmer ASLAKSEN is here Why Singapore is in the “Wrong” time zone ?
The conclusion is the natural time zone of Singapore is GMT+7 hours. Now, this answers why the hindu religions’ in-auspicious time zone start at 7 AM in Singapore instead of 6 AM; they have adjusted for this time difference. Now, that is Science.