Poor Sleep Makes People Poor: The Costs of India Standard Time

After Independence, India adopted a single time zone for the entire country. India spans as much 1,822 miles in the East-West direction or 29 degrees longitude. If India followed the convention of a new time zone every 15 degrees it would have at least two time zones. With just one zone the sun can rise two hours earlier in the East than in the far West.

In an original and surprising paper, Maulik Jagnani, argues that India’s single time zone reduces the quality of sleep, especially of poor children and this reduces the quality of their education. Why does a nominal change impact real variables? The school day starts at more or less the same clock-hour everywhere in India but children go to bed later in places where the sun sets later. Thus, children in the west get less sleep than children in the east and this shows up in their education levels and later even in their wages!

I find that later sunset causes school-age children to begin sleep later, but does not affect wake-up times. An hour (approximately two standard deviation) delay in sunset time reduces children’s sleep by 30 minutes. I also show that later sunset reduces students’ time spent on homework or studying, and time spent on formal and informal work by child laborers,while increasing time spent on indoor leisure for all children. This result is consistent with a model where sleep is productivity-enhancing and increases the marginal returns of study effort for students and work effort for child laborers.

The second part of the paper examines the consequent lifetime impacts of later sunset on stock indicators of children’s academic outcomes. I use nationally-representative data from the 2015 India Demographic and Health Survey (DHS) to estimate how children’s education outcomes co-vary with annual average sunset time across eastern and western locations within a district. I find that an hour (approximately two standard deviation)delay in annual average sunset time reduces years of education by 0.8 years, and children in geographic locations with later sunset are less likely to complete primary and middle school.

Addendum: The importance of sleep and coordination of sleep with circadian rhythms is also illustrated by the phenomena of teenagers who get more sleep and do better in school when school opening is better timed with adolescent sleep patterns. As a result, we are seeing a movement to push school opening times later for teenagers. Perhaps India will adopt a second time zone.


I'm sorry but I don't believe any of that nonsense about needing a lot of sleep to achieve. 5 hours sleep is sufficient, everything else comes down to character and work-ethic.

As a blogger, I have a pretty good metric of how much I accomplish in a day. I'd estimate the correlation between the number of items I post and words I write in a day is about 0.75 correlated with how many hours of sleep I've enjoyed over the last two nights.

5 hours sleep. I hope you aren't an airline pilot!

"needing a lot of sleep to achieve." You still haven't cracked the problem of writing British English. Must try harder.

"I find that later sunset causes school-age children to begin sleep later, but does not affect wake-up times. An hour (approximately two standard deviation) delay in sunset time reduces children’s sleep by 30 minutes. I also show that later sunset reduces students’ time spent on homework or studying, and time spent on formal and informal work by child laborers,while increasing time spent on indoor leisure for all children. "

yeet and yet
this is what the americans call summer vacation

international Clash day
all day
thursday 2/07/19

Good luck having everybody sleep 5 hours and don't complain if you some day end up on the wrong end of a traffic accident caused by a absent-minded driver.

How about if we all go on Greenwich Mean Time and then set opening and closing times based on local conditions? Does great things for timetables, you can move the opening/closing times you now move by Daylight Savings Time by just adjusting the stated hours. I don't think time zones would have been adopted if we had had the sort of world wide connectivity we have today, this is a good time to fix it.

underrated idea

Yep. This is infinitely better than daylight savings. We already have to live with the fact that people in our own city might get to work at 7am or 10am.

I'm surprised no one brought up the Swatch time: https://en.wikipedia.org/wiki/Swatch_Internet_Time

I visited Alaska in late June 1988. My impression was that due to the extreme length of days, nobody slept much. We did things like tee off for 18 holes of golf at 6:20 pm, finishing up as the sun set at 11 pm, and take kids to the playground at 10:30 pm. It was utopia for somebody like me: a night person who likes sunshine. Still, it didn't seem too sustainable.

But, presumably, Alaskans periodically crash to catch up on their sleep.

"But, presumably, Alaskans periodically crash to catch up on their sleep."


So, how does the great variance in time with daylight in a place like Alaska impact children's education relative to the lesser variation in Florida or Ecuador?

Too small of a data set. Alaska is all men, so there aren't enough children.

Christ, you Yanks take forever over a simple round of golf.

China has an even greater East-West length (5200 kilometers) and only one time zone. And their East is richer than their West, but there are plausible reasons for the difference that don't include standardized school starting times.

+1, was going to say the same thing.

Exactly. India doesn't really seem that bad. China would be the example to play with.

For comparison, the central time zone in the United States is about 1,300 miles at its widest which isn't that much less than Alex's 1,822 mile time zone width for India. People in West Texas and Florida Panhandle don't seem extremely bothered by being in the same time zone.

Actually El Paso and Pensacola are one time zone apart from the rest of their respective states due to the extreme distance.

I didn't say El Paso. Most of West Texas is in the central time zone.

To clarify my point, most of West Texas and the Florida Panhandle are in the same time zone (central) and at its extreme that spans about 1,300 miles.

+1 - not to mention Arizona, which does not use Daylight Savings Time.

Bonus trivia: DST is a disaster, because of: [parade of horribles here] and should be abolished.

And now, the type of intellect that brought us DST wants to get us a new green deal.

The article deals with schooling years, not wealth.

And the article cites a source which tells "an hour delay in annual average sunset time reduces children’s sleep by roughly
30 minutes" on Western China.

The issue here is poverty. If there's sunlight, those children have work to do, quite probably subsistence farming.

Where I live dawn starts at 4h30 during summer, since I have window shutters and an office job, I can sleep until 7h00 and go to sleep at 22h00 even if there's still light out there.

China has a wide range of distance, but most of the population is in the east [^1]. The two provinces that make up a bulk of western China - Tibet and Xinjiang - have a combined population of under 9 million. An eastern province, Jiangsu, has a population of nearly 79 million people. Total population of the country is nearing 1.4 billion.

So, even though China has a single time zones, a vast majority of the population lives quite close to each other. So, the impact of a single time zone is fairly limited as long as schedules are aligned to the east coast.

In India, on the other hand, states[^2] in both the east and the west are quite densely populated. Assam and West Bengal, in the East, have populations of 32 million and 91 million respectively. Gujarat and Maharashtra, in the West, have populations of 60 million and 112 million respectively. The impact of these states having a single time zone, despite the distance between their extremes, is fairly covered by the article.

Another interesting example here is Australia. Its population distribution is similar to China - most living in the East (17 of 24 mn), with a huge mostly-barren western half. Yet it has multiple time zones. Way too many (5!) if you ask me.

[^1]: https://en.wikipedia.org/wiki/Provinces_of_China#List_of_province-level_divisions
[^2]: https://en.wikipedia.org/wiki/States_and_union_territories_of_India#States

Pakistan is half an hour behind and Bangladesh is half an hour ahead of Indian Standard Time. The culturally distinct North East may deserve its own time zone but Hindu India is within half an hour of a spiritually significant meridian running through Prayag.
The author of the paper is looking a 5 minute differences in sunset time and claiming to find an East-West gradient on that basis. This is implausible. https://socioproctology.blogspot.com/2019/02/junk-social-science-from-maulik-jagnani.html

I dunno. In the US, it seems to me the Central timezone runs about an hour earlier than the Eastern timezone, in order to sync up.

The Western US runs on its own schedule, but now you're talking 3,000 miles. Even here, I suspect the day starts and ends earlier according to the clock than on the east Coast.

Nope. We in central time start hour late than Eastern time. Anyone putting 7am meetings from east zone because it's their 8am isn't tolerated after one or two exceptions. We openly tell EST people to not call before our business time.

"Time zones are different sizes. Poor hardest hit."

Holy cherry-picking. Do the same analysis in the other 25 places where this disparity exists, and get back to us.

Even with separate time zones, people throughout the United States (from Hawaii time to Eastern time) don't go to bed at radically different times. Brooklyn has the latest average bedtime for any timezone (around midnight) wheres Maui has the earliest average bedtime for any timezone (around 10:30PM). Despite being a quarter of the way around the world from New York, people in Maui go to bed only 3-5-4.5 hours later. There is probably a rural-urban effect at play here, but I wouldn't be surprised that their is some sort of nationalized standard at play here (i.e. Californians waking up early for conference calls based out of DC, the stock market closes on Eastern time, live televised events).

I can't get the url for my source to load, but you can see the map of average bedtimes by county at this site: https://abc7chicago.com/health/up-all-night-average-bedtimes-and-hours-slept-by-county/345188/#gallery-1

When I worked in California, but was working on projects in the Southeast, I found myself adjusting when I came into work based on the times my coworkers came in. I'd be in the office at 6:00 or earlier routinely. Which was nice--I'd get off work around 3:30/4:00, and would miss the worst of the 405s rush hour.

In a building with 200 units (anywhere in the world) sleep schedules will vary. It is tied to our financial and mental health situation. In a competitive environment people may only sleep 3.5 hrs due to stressful conditions. Doesn't mean it's normal or a standard for that region. Biologically we are still a part of nature and body wants to be in sync with sunsets and sunrises. It's especially harder for kids to adopt to urban and school clocks than anyone else.

I really don't know so I'll suspend judgement but 3 things stand out at me:

1) I feel that much of the idea originally (as in an agricultural sense) is helping children grasp the need to program their days around things needing to be done not vice versa. I'm not sure that this idea still doesn't have some applicability.

2) Someone mentioned China above. +1. But there are other examples that can be seen in Russia, especially the Soviet era. Not so much unitary time zone, but lack of tolerance for disruptions caused by significant shifts in time zone.

3) Regarding later school times, what about significant impacts made on peoples' lives that aren't school children? The standard working, business, awake hours of everyone else don't change which means disruption and economic impacts on the other end of the spectrum for everyone forced to adjust.

I'm left wondering if the 'juice' of chronological adjustment in education for kids is 'worth the squeeze' in such a scenario. I'm not talking about children in extreme environments like Alaska, which I exempt, but in this situation specifically.

Let us be blunt. It is savage regime controlled by Satanism.

And what if you are really blunt?

I am very blunt. I never make bones about totalitarian regimes.

mommy, mommy
is malcom gladwell gonna ruin summer vacation
also what exactly is this international clash day 2/7/19
we keep hearing about?
es este jueves

There is nothing necessarilywrong with having a single time zone, it's the inability of the schools to change the start times accordingly.

In the 24/7/365 (366) world that our lying and spying Tech Establishment has given us, who NEEDS sleep?

We're no longer animals: we're practically all machine nowadays (so we are being invited to think and believe and perform), and machines NEVER sleep.

No one among us today can be thought or said to have a life unless he's plugged into our tech-driven treadmills 24/7/365 (366). --so who NEEDS sleep? (Think for two moments JUST HOW MUCH YOU COULD MISS were you to indulge in a solid eight hours of sleep: entire awards show broadcasts--even entire media careers--could pass you by!)

Has our lying and spying Tech Establishment not yet equipped us with the incentives and apparatuses and tools we need to maintain constant vigilance? (If not, why not? If phenmetrazine hydrochloride worked for the Beatles, we should immediately socialize production and distribution, some could argue.)

The only moments today accorded any significance are WAKING MOMENTS: to hear our Tech Establishment cheerleaders tell their tales, sleep enjoys no more enduring utility in 2019 CE than stone axes might possess. (Our lying and spying Tech Establishment still has a lot of unheralded trouble in acclimating itself to subjective human states.)

Needs more caps.

An ample plenitude, no doubt, but there's no accounting for taste.

I'm not so averse to caps here in the MR Forum, since we have no conspicuous option for underlining or bolding text.

End Daylight Savings Time Now! For the children (and my health).

Or keep it all year. I like the extra light in the evening.

Consider moving to western China, perhaps to Urumqi. The sun sets there around 8:22pm on average (solar noon occurs at 2:17pm on average). Near the winter solstice the sun sets a little after 6:30pm and near the summer solstice the sun sets a little before 10pm.

“...estimate how children’s education outcomes co-vary with annual average sunset time across eastern and western locations within a district.”

I doubt if there is a single district in India where the eastern and western ends have sunset 1 hour apart. Maybe this is just a poorly framed sentence and the author is actually comparing 2 districts with 1 hour difference in sunset times.

I glanced through the paper and did not find any information on which districts were selected for comparison. For example,Mumbai and Barmer (In Rajasthan state) have about same sunset times yet have wildly different education outcomes. Or Kolkata and Bhagalpur (Bihar). Or Chennai and Prakasam district (AP state).

Wihtout knowing which districts were selected in east and west, one suspects some cherry-picking might have happened.

I have yet to read a sleep study that addresses the elephant in the room: New parents suffer sleep deprivation that is rivaled only by certain torture methods. If sleep deprivation caused all the doom-and-gloom horror that it supposedly does, the human race would simply have ceased to exist by now. Yet we persist. So quite obviously there is more to the story here--yet to the best of my knowledge (I'm not an expert, but I have kept my ear to the ground on this), this issue has never been addressed.

So in my opinion, all sleep studies fall under the heading "Interesting, needs further research, there are some serious, substantive concerns".

Kinda strawmanny. No one is saying "doom and gloom horror" they are saying some kids have lower test scores. Hardly a species-threatening problem.

I see where you're coming from, but my point still stands, for two reasons:

First, until VERY recently most people became parents young. Teenage parents were the norm until the Industrial Revolution. And babies haven't changed much. While the rich could afford to have wetnurses and other folks to care for the kids, the poor were on their own--which means sleep-deprived. There are ample texts from pre-industrial eras to support this. This is never addressed. If they want to say "Well yeah, but people back then were dumber than they are today" (or the equivalent) that's fine--but they need to actually address the issue, and that's not being done.

Secondly, while this one report may not be "doom and gloom horror", this report isn't isolated. "Lack of sleep causes X bad thing" is a common headline, and research into the negative effects of sleep deprivation is increasingly common. Taken in aggregate it seems like the sleep deprivation associated with having new children WOULD be a species-threatening problem; all the health problems attributed to sleep deprivation should be culling parents at an alarming rate. Yet we don't see that.

I'm not saying these are critical flaws in the research. What I'm saying is that this entire area of research is missing a very significant counter-argument, and that this causes me to believe that the field simply isn't mature enough to draw many firm conclusions. It's not that I think the research is wrong; I don't think that the field has studied its available data sufficiently to BE wrong or right. (This is no insult, by the way--if you look at the history of any scientific field they ALL go through such a phase.)

The whole adolescent sleep thing seems fishy to me. It seems to be promoted by parents of high school kids who want more flexibility in their own schedules. The animal studies seem pretty inconclusive and cherry picked. To parents I say: They're still minors; tell them to get in bed earlier if you're so concerned.

Spain and Germany are in the same time zone.

France and the Low Countries used to have their own time zones. Hitler rationalised that. It's striking that after The War they didn't revert.

Franco changed Spain's time zone during World War II. Spain should be on the same time as the U.K.

Two comments:
1) Western India is richer than the East no? Gujarat, Punjab, Maharashtra and Kerala are richer than West Bengal, Orissa Bihar etc. So this mustn't have a big effect unless the west has many other advantages.
2) What did the time zones look like during the Raj?

1. The rich-poor divide in India is north-south, not east-west. 2. Good question, I'll ask my research guru.

That's fair enough about north-south, but I think within both north and south India, western states are in general richer (exceptions: Rajasthan and Karnataka?).

I found out the Raj time zones, there was essentially one for each presidency i.e Calcutta time, Bombay time and Madras time. There was an additional one for the Andaman Islands.

Since Indian Stretchable Time (IST) is based out of a fairly central city, Nagpur those in the extreme east are as far out of sync with it as those on the extreme West.

it's mirzapur not nagpur

Confounded by genetics.

There could be tons of other factors influencing why there is a performance discrepancy between East and West India. Also, why would children in places where the sun sets later have more indoor leisure time? It would be much better if the article also provided some explanations about the claims.

Another thing is that in places like Northern Europe, the sun sets much much later in the summer. Does everybody's performance get negatively impacted in the summer? There are certainly many more complex factors at play.

Ever wondered why Spanish eat so late?

Because, thanks to Franco, who changed their time zone to Berlin's in 1942, their biological clocks are screwed up.

Valencia is actually on Greenwich meridian.....

In my book Mystery of Sleep (https://www.krygerbooks.com/mys), I write about the crazy time zone of Spain, and explain that Spain is in the wrong time zone (it has to do with sun light exposure, which resets the circadian clock), making it a nation of night owls who eat and sleep later than the other countries in Europe.

Any bets on whether this study will replicate?

here in brazil we have 4 time zones [ official time, +1 hr on the oceanic islands, -1 hr in central-west and western amazonia, -2 hr at peru border ], eventually 5 (!) during daylight saving in summer. it's a mess. some brazilians do well with d.s.t. (that we call 'summer time'), but most don't, even in coastal cities, where extra sunny hours invite to the beach. instead of adjusting clocks, it would be much simpler to adjust school, work & services times!

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