Out of Sync Time Zones

In today’s Classical Column a1_124, Cecil ends the column with " I can’t explain Saudi Arabia, but nobody else ever has either." That was said about the fact that in Saudi Arabia, the first hour of the day starts when the Sun Sets, thus 1 O’Clock occurs exactly one hour after sunset, and 12 O’Clock occurs exactly 12 hours after sunset.

That hardly needs explaining. This was a very common practice in the mid-east. Not only did was this the Saudi custom, it was an Arab custom and a Jewish custom. It is mentioned in the Jewish Scriptures (Olt Testament) and it is mentioned in the Koran. The Saudis believe that setting the time this way is a commandment of God, thus they continue doing it today.

Cecil probably could have answered this in 15 paragraphs or less. I did it in two.

And the column being referenced is, Why is India 30 minutes out of step with everybody else?

Cecil didn’t need to answer it, as the question concerned India’s time zones, not Saudi Arabia’s. But thanks anyway. :slight_smile:

The clocks in Saudi Arabia were mentioned again on p. 262 of More of the Straight Dope. (It’s back in print and you can buy here). In chapter 22 (“Feedback”), a correspondent says that Saudi Arabia no longer resets the clocks daily.

FWIW, Australian Central time is 30mins behind Australian Eastern Standard.

However, and with apologies to our croweating bretheren, Adelaide time is not commonly seen on the worlds public time pieces.

With partial adoption of daylight saving, Australia at this time of is the land Standard Time forgot.

Wow - I was composing my reply to the original, and this one had already happened. Naughty, naughty! See this…


Yes. I think that Cecil or one of his minions should add the clarificatory correspondence re. Saudi Arabia into the column as available on the website, lest hordes of indocts write in and correct something he knows already.

While a staff report about the British Isles by C K Dexter Haven gets taken to task for being condescending :


and defended because “the information being requested was available almost anywhere”.

the man himself, i.e. Cecil, manages to divide the British Isles into two time zones; England and Ireland.

I guess the rest of us just didn’t have clocks?

Just to pile on: Cecil was also misinformed about Nepal.

Nepal Standard Time is UTC/GMT + 5:45 (there is no Daylight Savings Time).

Nepal is one of the very few areas of the world where the local time offset from GMT is not a full hour or half hour. I believe Chatham Island, New Zealand is another, but I haven’t heard of any others.

I don’t know why Nepal has such an odd offset. The only explanation I had while I was there was that Nepal wanted a different timezone from India to emphasize its independence from its much larger neighbor.

I will say, however, that it often doesn’t matter. 15 minutes one way or the other is par for the course in much of Nepal. I met one tourist who had arrived from India and had spent a whole week in Nepal before realizing her watch was off by 15 minutes…

And at the time Newfoundland settled on its time zone, it was not a part of Canada. It didn’t join Canada until 1949.

One time zone anomaly I haven’t seen mentioned (although it falls under the broad range of Asia) is that the People’s Republic of China has only one zone. The country is as large as the US, so you might expect three or more zones, but all China reads time as +8 hours GMT.

There is nifty time-zone finder at http://www.hilink.com.au/times/.


Speaking of local time-zone differences, the state of Arizona does not follow Daylight Savings Time (DST) as the rest of the United States does (first Sunday in April to last Sunday in October). During standard time, Arizona clock time is Mountain Standard time; but while the rest of the zone is using Mountain Daylight time, Arizona clock time is one hour behind , and so the same as Pacific Daylight Time. Keep this in mind when flying into Tucson in the summer.

And while I’m on the subject, I’d like to point out the contradiction of calling it “standard time” when we use it for only five months out of twelve!

Arizona isn’t alone. Other parts of the U.S. decline to follow Daylight Savings Time as well.

According to Heidi G. Yacker of the Congressional Research Division at the Library of Congress in this paper, http://webexhibits.org/daylightsaving/congressionalResearchService.html,

It’s called “Standard” because:

A) It’s the one adjusted to have the sun roughly overhead at noon.

B) It’s the original. DST is a departure from it.

And don’t overlook that, prior to the adoption of standard time in the US, many cities had their own time. Just because you were in the same state, your time might well be 10-20 minutes off of of another city in your own state.

Now, I don’t know if this is a crock or not, but for those former British empire countries that are 30 minutes off (India for example), are because back in the good old days, to calculate the time difference with Mother England, you turn your watch upside down and subtract xx number of hours. Voila, there is a 30 minute difference.

Anyone out there with more info on this, which was sworn to me by some people who had just spent a considerable amount of time in India been serious tourists or getting the wool pulled over their eyes.

I’m deeply suspicious of this explanation. How far back are the “good old days”?

For a quick and cryptic history of timezones in India (and throughout Asia), take a look at this file, http://www.math.nus.edu.sg/aslaksen/teaching/hm/asia.txt. It’s part of the tz database that Unix computers use to calculate local times. If you scroll down about a third of the way you’ll see a section for “Asia/Calcutta”.

Apparently Calcutta time was first standardized as GMT + 5:53:28. I don’t know when this started, but it continued until 1880.

From 1880 to October 1941, Calcutta time was GMT + 5:53:20.

From October 1941 to May 15, 1942 there was a switch to Burma Time (GMT + 6:30).

Indian Standard Time (IST) started in May 15, 1942. There was a brief flirtation with Daylight Savings Time during WW II (from 1942 through 1945), but since then it’s been GMT + 5:30 year round.

Thus, considering the odd offsets of Calcutta time up until 1941, I don’t think the “turn your watch upside down and subtract an even number of hours” trick could have worked. Certainly not back in the days of the Raj, anyway. I also note that other English colonies in Asia (such as Singapore and Malaysia) had equally odd time offsets early in their colonial history.

Wait… If you’re going to be subtracting hours anyway, why bother turning your watch over?

Maybe he got his causation backwards. Because India is offset 30 minutes, you turn your watch over. Then you subtract the requisite hours.

I posted in the other thread that rampisad linked an explanation of why countries had and retain offsets not equal to hour increments. I’ll try to paraphrase. The intent of local time is to conform as closely as possible to noon = sun directly over head. (This is of course muddied by daylight saving time, but we’ll ignore it.) However, difficulty arises when two geographically close locations use different times - confusion results. Ask anyone who lives along a time zone border. For large political entities (i.e. the United States), it is convenient to divide into 1 hour swaths that are 1 hour increments off GMT. This makes converting time zones easier. There are always going to be regions at the edges of the time zones that are not completely happy with this arrangement, but the alternatives include going to 30 minute time zones, which makes local times better but adds more cross time zone confusion.

However, if your political entity is geographically small such that it doesn’t take up large wide bands (multiple hour swaths), then a different condition exists. If your small political entity is only as wide as, say, a quarter of an hour swath, it makes sense to calibrate the whole entity to one time zone. Further, if you are located near the edge of a 1 hour swath, your local time will not correspond to noon = sun overhead unless you calibrate your location. If you calibrate the location for approximating noon = sun overhead, you find the offset from GMT doesn’t correspond to an even hour increment from GMT. So you have a choice - offset the clocks and retain sun overhead, or match clocks to the nearest 1 hr increment and deal with the sky not matching expectation. :wink:

Which of course would most certainly not apply to India, which runs some 30 degrees wide East to West, enough for two whole time zones.

It gets even worse than that when one drives around the area, because, IIRC, some of the Indian Reservations within AZ actually do observe DST, so keeping your watch set correctly turns into a real challenge!