The Trans-Siberian railway crosses seven time zones from Moscow to Vladivostok. Image Credit: Supplied picture

Crossing the border between eastern Turkey and Iran on a frosty November morning some years ago, I found myself at the heart of a sprawling compound straddling the two territories. Growling oil trucks with big engines lined up in endless rows, ready to ship black gold along the Anatolian Highway into Europe, dripping sticky dark puddles as they waited in the chilled air for customs clearance.

Independent travellers had to negotiate their way through the tanker lorries and eventually be ushered into an oblong room having had their passports ‘stamped’ out of Turkey, but not yet admitted into the Islamic Republic of Iran. It was a curious, sheltered no-man’s land east of the Turkish town of Doğubeyazit. On the Turkish wall, the paternal figure of Mustafa Kemal Atatürk looked down on departing visitors. As I lifted my eyes, they locked with portraits of Ayatollahs and Iranian Presidents.

Momentarily transfixed, I then subconsciously noticed a red-tiled line passing across the ceiling, down each wall and across the floor. I was standing astride what I realised was the border between the two nations. What I didn’t fully appreciate until I arrived in Iran, was at that very moment, my left leg was one hour and 30 minutes behind my right leg. Fortunately, I suffered no lasting physical or psychological fallout from the experience.

It did, however, illustrate to me the human ability to play with time and nature, with nations adapting time zones to suit sovereign interest or seize economic advantage. While the position of the sun has always decreed our daily routines, it was not until 1884 that the world was formally sliced into a 24-hour clock, with longitude zero degrees at Greenwich in London and longitude 180 degrees – the imaginary dateline that separates days – running through the Pacific Ocean.

However, since that segmenting of the globe at the International Meridian Conference, some countries have subtly shifted their time slots to formally separate themselves from neighbouring states, ensure optimum use of natural daylight or affirm national and political identity and individuality.

Pakistan is a perfect example; it moved its clocks back half an hour in the 1950s to emphasise its separation from India after the division of the sub continent in August 1947. Even quirkier, perhaps, is Nepal, where the time difference once you cross the border from northern India is a mere 15 minutes.

Perhaps most dramatic is Samoa’s leap in time. Set 30km east of the International Date Line, it skipped a whole day at midnight on December 29, 2011, going straight to December 31 to fall in line with Australia and New Zealand to strengthen trade links with the two countries. The move came 119 years after Samoa moved in the opposite direction when it wanted to improve trade links with the US.

It’s all in the rhythm
Time zones, a necessity of modern commercial living, only really have any impact on us as individuals and our physical, mental and emotional wellbeing, when we start to cross them as frequent flyers. And the more we zigzag back and forth, the more we need to be aware of the impact on our health and ability to perform effectively.

Flying west to east is where jet lag can often be at its worst – red-eye flights from the US to Europe or right across the Middle East and into south-east Asia play most havoc with the body’s natural balance.

Sleep and time expert Professor Josephine Arendt from the Centre for Chronobiology at the University of Surrey in Guildford, UK, says crossing time zones affects the body’s natural circadian rhythms, which influences our sense of time and place.

“The so-called circadian rhythms will be out of synchrony with the new time zone for several days, depending on the number of time zones crossed. The most perceived problems are usually people feeling tired and sleepy during the day, with problems getting to sleep going east and problems waking up going west.

“If people are staying in the new time zone for more than two days, it is best to try to adapt the body rhythms to some extent before travelling – by going to bed earlier before going east and later when going west,” she suggests. Crossing time zones affects sleep, body temperature, alertness, cognitive performance, digestion and hormones, but there are ways to minimise the impact.

Timed exposure to bright light and trying to eat meals, exercise or sleep at the appropriate time for the new time zone can help. But for those who cross time zones constantly, it can be difficult to adapt, with the severity of jet lag often correlating to the number of time zones crossed. There is little data on the long-term health risks of crossing time zones often, but airlines offer advice where they can.

British Airways has a jet lag calculator on its website, designed to offer advice – depending on times a traveller normally gets up, and the time it is in their country of departure and destination – to help minimise jet lag. It also seems there may be an impact on athletes from crossing several time zones.

During the 2012 Olympic Games, research conducted at the Institute of South Africa in Cape Town suggested that athletes who compete at major events in their home country are at an advantage, because those who travel across more than five time zones to get to a competition are more likely to get ill. The research, published in the British Journal of Sports Medicine, noted that most of the illnesses were infections, respiratory problems and stomach bugs.

Zone hopping
While the frequent flyer most acutely feels the impact of crossing time zones, it is those who travel at a more sedate pace over land who truly experience the quirks and delights of these horological delineations. Time zones bend somewhat haphazardly down the globe, and some of them are not always easy to understand or live with. Take Indiana, US, which has two time zones, as it straddles Eastern and Central time in the US.

Meanwhile, Russia and China, two of the largest land masses on earth, have approaches that could not be more different. From west to east, Russia is 10,000km and is covered by nine time zones (reduced from 11 a few years ago), while China – which stretches 5,200km from west to east – is covered by one single time zone centred on Beijing, where once it had five.
 
And there are quirks within this; when travelling by train in Russia, all trains and stations operate to Moscow time, whether they are Vladivostok, Irkutsk, Murmansk or Saint Petersburg. It means you can stand on the street in central Siberia at 9am, but the moment you cross the station threshold, you readjust your watch to 6am. And in the Arctic, where the borders of Russia, Norway and Finland meet, there are three different time zones within a few paces.

When it is 2pm on the Norwegian side, it is 3pm on the Finnish sector, while a short step away in Russia, it is 4pm. In Antarctica, where all the time zones converge, scientists work on all different times, generally picking the one that suits them. But it barely matters for long periods of the year, as it is either daylight or dark all the time.

Of course, further complications arise when states put their clocks back or forward to eke out the most from the daylight hours – when GMT, for example, becomes British Summer Time in the early hours of a Sunday morning in the UK in late March every year. But amid these time-zone quirks, there is a group of monuments that remain transparent and honest in their reflection of time.

Across central India stand a chain of giant astronomical instruments constructed by an 18th-century king to measure the position of stars, and with massive timepieces telling the time of day to the nearest minute from the position of the sun. Known as Jantar Mantars, four of the colossal pink structures of Maharajah Jai Singh survive – the best known being in New Delhi and Jaipur.

As you stand in central Delhi with your watch set to Indian time, there is precise correlation between the Jantar Mantar and your timepiece. But heading west to Jaipur, east to Varanasi or south to Ujjain (a fifth structure at Mathura has long-since disappeared), the sundials will show slightly different times – all accurate to the sun, but not quite correlating with your wristwatch and the modern time zones the world is divided into.

What the Jantar Mantars demonstrate, is that the world does not naturally carve up into hourly slices of modern time zones, but is a precise science inextricably linked to celestial bodies and the human body clock. And it shows us that, however much we play with time, one thing is certain: nothing will stand in its way.