But above all else, he’s an advocate for changing Indian Standard Time (IST).
Sengupta and research partner Dilip Ahuja, 68, were in Mumbai on 18 March for a talk at the Observer Research Foundation. The lecture, ‘Energy and non-energy consequences in adjustments in Indian Standard Time’, was their latest in a series on why IST should be pushed ahead by half an hour to UTC+6:00 instead of the current UTC+5:30. These lectures, spanning 10 years and about as many cities, from Thiruvananthapuram to Delhi, take off from their 2011 study—one which is almost always footnoted in articles or rebirthed in research papers about why India needs a modified IST.
Time is anything but objective. Our hours, minutes, and seconds are dictated by atomic clocks so precise, they won’t gain or lose a second in millions of years. Their exacting nature is why the International Bureau of Weights and Measures (BIPM) uses them to define UTC, or Coordinated Universal Time, as the basis for civil time. All countries, in turn, align to their assigned atomic clocks that march to the BIPM drum.
But even precision bends to the whims of our earth. The tilt of the planet’s axis, the churning of tectonic plates and the tides of the moon tease man-made time every now and then, reeling it in a perpetual game of catch-up. Here’s an example: the moon, through the power of tides, is slowing the earth’s rotation. This means our days are getting longer—by 2.5 milliseconds every century.
For satellites, aircraft, sportspeople and just about any kind of programming for which milliseconds are make or break, this is everything. The slower the earth gets, the faster the millisecond-gaps will pile up. In which case, a leap second will be added more regularly to the UTC than it is today.
If one millisecond can do this much, imagine the chronological chaos that once was in a country as extensive as this. India’s longitudes span 68° 7′ east to 97° 25′ east. That’s almost 30° of longitude, while time zones roughly change by one hour every 15°. The sun that rises at 4:30 AM in Arunachal Pradesh at the northeastern tip of the country rises at 6:30 AM in Gujarat in the west. If dusk awakens at 4:30 PM in our eastern flanks, it doesn’t do so until 6:30 PM in the west.
Small wonder then, that the states of Arunachal Pradesh and Assam consistently demand a separate time zone for northeast India. There’s even a private member’s bill in Parliament for this. It’s unfair, they feel, that the IST meridian passes through Mirzapur, Uttar Pradesh, where average sunrise and sunset times are “closer” to those of western India.
But Sengupta, on finding his newspaper clipping from 1976 about 15 minutes into the conversation, relays why he’s believed—for 43 years now—why two time zones won’t work:
“‘The article ‘Daylight Saving for India’ by Mr Harry Miller, dated 6 February, is thought-provoking. But different times in different parts of India will lead to instant chaos. I can visualise trains running into each other and airline schedules going haywire’,” he reads out from his letter to the editor at the time. “‘One can instead consider energy savings that may be achieved advancing IST by half an hour.’”
Resting clock face
It’s one thing to want a change in official time, and another to demonstrate that doing so can yield benefits. The burden of proof is heaviest for a scientist. And so, Sengupta’s hunch about the advantages of advancing IST remained just that, until Dilip Ahuja came into the picture.
In 1982, Sengupta addressed a Delhi conference on energy data systems and how using daylight to the maximum may lead to energy savings. Ahuja, a former ISRO professor of science and technology policy at NIAS who’d researched electricity deficits, became interested. The two got in touch, collaborated in NIAS and in 2009—27 years later—finally got funding to undertake what would become the most extensive study for a modified IST.
Their findings, published in 2011, showed that advancing IST to UTC+6:00 would save 2.1 billion kilowatt hours or 17.5% of “peaking energy” (power demand during peak or evening hours) a year. In monetary terms, they put that at Rs 1,250 crore to Rs 1,450 crore annually (roughly $270 million to $310 million at the time), after accounting for the costs of switching time zones. And these are 10-year-old figures. Ahuja reckons the energy savings would be about 3.5 billion kilowatt hours a year today.
“Dr Sengupta specifically developed methodologies to estimate potential energy savings, which was a first,” Ahuja says. It reportedly took a panel, finalised by the Bureau of Energy Efficiency (BEE)—the chief funding agency that provided Rs 30 lakh ($43,250) for the research—to vet this methodology.
Why was this a big deal? Because household meters in India read total electricity consumption across appliances. There’s no way to measure how much energy is used just for lighting, for instance. But you can use statistical averages for random data. In this case, a pattern that emerges about the random action of flicking a switch on or off.
Getting published in Current Science, followed by Elsevier’s Energy Policy, got them a meeting with T Ramasami, the then secretary of the Department of Science and Technology. Ramasami asked Sengupta and Ahuja to analyse load curves of individual states, rather than zones (north, south, east, northeast, west). They obliged, building on their 2011 study three years later, again in Current Science. They’ve also written article after article on their pet cause.
But reward isn’t obligated to follow effort. Circa 2019, there’s zero inclination to modify IST. Why?
“We could never meet ministers. It was always secretary this, secretary that,” Sengupta says. “We even made presentations to the power sector. One official from the ministry of power vociferously called to push this further. But that’s all it was… platitudes.”
Indifference often stings deeper than rejection. Ahuja, now in the US, where he spends half the year, adds that there’s no clamour for a new IST outside the northeast. Mainland India’s lives are so entrenched, we don’t give optimum daylight use any thought. More importantly, Indian governments over time, on whose ears northeast India’s time zone demands fall every now and then, are disinclined for “strategic reasons.”
“Now, our stance against a region-specific IST is scientific, based on the fact that it wouldn’t give benefits a half-hour advancement across the country would,” Ahuja elaborates. “Others don’t care because the accrued annual savings amount to ‘just’ 0.3% of total energy consumption. But what they fail to gauge is the significant reduction in evening loads, leading to hundreds of crores in monetary savings. More so at a time when coal consumption for power generation is rising.”
Government apathy is one thing. But what does India’s official timekeeper think?
The NPL angle
The lives of almost all Indians are tuned to the frequencies of five caesium atomic clocks. These devices, tuned to BIPM standards, are housed in the Time and Frequency Standards division of the National Physical Laboratory (NPL), New Delhi, in turn a division of the Council of Scientific and Industrial Research. The NPL, as our national arbiter of measurements, is the most important stakeholder in discussions about time standardisation. Turns out, its director DK Aswal isn’t on board for a modified IST.
“Because our study from late 2018 clearly shows a second meridian of UTC+6:30 at Alipurduar, on the border between West Bengal and Assam, would save more energy than a half-hour advancement nationwide,” he says.
This NPL study, in Current Science, is all of 10 pages. Except for an equation to calculate potential annual electricity savings, there’s no detailed methodology or even citation of where energy data is sourced from (Sengupta and Ahuja’s data 10 years ago was sourced from the Power Grid Corporation of India). Instead, NPL’s footnotes include an article from The Hindu and five entries from Wikimedia Commons/Wikipedia. Perhaps this is more telling of Current Science, supposedly India’s leading peer-reviewed interdisciplinary sciences journal.
“Their (Sengupta’s and Ahuja’s) estimations were wrong. We did calculate potential savings for a UTC+6:00 scenario, but didn’t publish that or a detailed methodology because of word count constraints,” Aswal says. “Besides, the current UTC+5:30 meridian works because it’s in the centre of the country. Shifting it east for the sake of UTC+6:00 will create the same problems for the west that the northeast now faces.”
A fair point. In fact, a December 2018 paper by Cornell University researcher Maulik Jagnani reveals how sleep and economic productivity in western India are already hampered by late sunset times. Switching to a dual time zone setup—UTC+5:00 for the west and UTC+6:00 for the east—he estimates, could result in “net human capital gains” of $4.2 billion.
Sengupta, over the phone from Bengaluru, still defends the UTC+6:00 proposal, saying it would condition people in the region to inadvertently wake up and sleep earlier. You would still retire at 11 PM and wake up at 7 AM as you do now, he explains. But the new time will show 10:30 PM and 6:30 AM, respectively. You’ll just be optimising morning light and using artificial evening light to a lesser degree, is his take. It’s a debate that may never be settled.
“The economy is mostly controlled by western India, so I wouldn’t rule out political complications here,” the octogenarian concedes. “If the east doesn’t want to lift the west’s time burden today, the west wouldn’t want the same tables turned tomorrow.”
Sometimes, even painstaking research, for all its buttressing by data and vetted methodologies, misses out on the big picture. Nowhere is this more evident than at Rajabai Clock Tower, just a 10-minute walk from Sengupta-Ahuja’s last lecture at the Observer Research Foundation.
Much ado about nothing?
The absence of mobilisation for a new IST is better addressed by history than science. For 10 of the 19th century’s twilight years, the iconic clock tower in Mumbai (then Bombay) didn’t even function because there were debates, columns and riots over what time it should display. While “God Save the King” and “Rule Britannia” chimed from Rajabai tower, Bombay danced to its own tunes. The city once had three time zones—Standard or Madras Time, Railway Time and Bombay Time. The first two, seen as colonial impositions, weren’t taken to kindly.
The Industrial Revolution warped our collective sense of time and distance with its steamships, engines, and telegraphs. This first era of globalisation also required standardisation of measures across continents and colonies. You can bet this was a merciless exercise.
Our circadian rhythm, more in tune with the earth than a mechanical clock, instinctively obeys sunrise, afternoon, sunset, and solstices rather than an hour, minute, and second hand. The knees of official time, then, are as wobbly in the face of human resistance as they are with our planet’s eccentricities. Kolkata (then Calcutta) also had its own potpourri of times, as did the American Railways, Germany and west Asian countries.
“Time zone decisions tend to be political rather than scientific. Official times rarely align with longitudinal or solar times, which is why they’ll always be ‘off’ by a few minutes to a few hours,” Shekhar Krishnan underlines. A historian and anthropologist, Mumbai-based Krishnan is turning his thesis on the link between colonisation and standardised time into a book.
The gist is that officiating clocks makes little sense in sociocultural contexts where regions abide by their own times. Why not change office hours across regions instead, Krishnan asks. It’s a valid question. “9 to 5” and “10 to 6” routines make no sense in areas where the solar day starts at 5:00 AM.
“Clock time also doesn’t matter to a largely agrarian population, except when it interacts with industrial society, mostly through marketplaces and banks, which abide by official time,” Krishnan adds. “So one must consider whether any change could hamper them.”
Common standards, like languages and measures, are necessary. But is there a naïveté to attaching more significance to IST than it deserves? Is this the same naïveté we attach to pedometers that measure 10,000 steps from GPS data? The same naïveté we attach to calorie counting?
It’s one thing for the humanities to deem a scientific study socially insignificant. But another for a scientist, once associated with the same study, to imply that what mattered then doesn’t matter now.
That scientist is Ajay Mathur, director-general of The Energy and Resources Institute. Mathur, who took over from former disgraced institute head Rajendra Pachauri, was the director-general of BEE when the organisation funded Sengupta and Ahuja’s research. His expertise in energy efficiency makes him a go-to for enquiries on whether time-tinkering would decrease power consumption. And whether the UTC+6:00 argument holds stead 10 years on.
To kick off, he inadvertently dismisses NPL director Aswal’s claim that estimations in the 2011 NIAS study were wrong. It was a robust methodology showing an opportunity for energy savings during peak hours, he adds. Government officials just didn’t think projected annual savings of 0.3% was worth the trouble.
But more importantly, energy savings can’t be the fulcrum for any argument on IST, Mathur adds. Because India no longer has the electricity deficits it did a decade ago. One can assume that any benefits accrued by an IST change would be less today.
Even the NPL’s argument for two time zones, propelled not by potential energy savings but our circadian rhythm, has no takers in the government. DK Aswal claims that their paper was read by “just about everyone in power”, but there’s no feedback yet. “Our responsibility is to publish data and inform people. It’s up to them (the government) to act or not,” he concludes.
Sengupta and Ahuja have resigned themselves to indifference. But they continue to give lectures, dispensing UTC+6:00 nuggets to whoever’s willing to have them. It’s a jugalbandi (duet) in which the sprightly Sengupta, in his slightly faltering voice, explains methodologies, while mop-haired Ahuja explains the results. Not unlike the symbiotic relationship between the earth and the moon that causes vagaries in man-made time.
“You tend to be pragmatic when you’re our age,” Sengupta says. “I hope IST modification will become a reality. But even if it will, I won’t be around to see it.”