By: John C. Wohlstetter

On the evening of Sunday, September, 5, 1999, two pairs of Arab terrorists planned to plant bombs on a pair of intercity buses filled with passengers, destination Jerusalem. One car headed for the Haifa terminal and the other for the terminal in Tiberias. Prior observation had revealed that these buses were not routinely searched by Israeli security. One team member of each pair would board a bus, and place a luggage bomb with 15 kilos (33 lbs.) of explosive in the baggage compartment. Each member would get off the bus at an interim stop and rejoin his comrade, whose vehicle was to follow the bus. Upon retrieving the bomber, each car would escape before the simultaneous Jerusalem detonations at 6:30 PM on Sunday, September 5.

Enter Father Time. At 5:30 PM the car headed for Haifa was at a rest stop, while one member got a cup of coffee, en route to a 6:30 PM date with destiny in Haifa, the bomb exploded, killing his partner in the car. Sixty miles away, in downtown Tiberias at almost the exact moment, the second bomb detonated in the car, killing both. Each blast destroyed much surrounding property, but neither harmed innocents.

Israel, a global outlier, had returned to Standard Time early on Friday, Septernber 3. But the Palestine Authority, along with most countries, including most Arab countries, did not return to Standard Time until early on Sunday, September 5. Both bombs had been assembled by West Bank Palestinians, and were set to detonate at 6:30 PM West Bank local time. The recipient terrorists had neglected to check for this temporary time discrepancy. Thus, both bombs detonated at 5:30 Israeli local time, an hour early. Daylight Saving Time, that fateful day, lived up literally to its name.

The story of Daylight Saving Time (DST)—an “s” added to Saving is deemed equally acceptable though formally incorrect—was superbly told by author David Prerau in Seize the Daylight (2005). The pre-DST tale of time travails begins with the ancients, and before getting to DST traverses several intermediate phases. Author Prerau traces the evolution of time measurement from the sundial, though Greenwich Mean Time (GMT) and the 1883 adoption of Standard Time, after which the prolonged saga of DST commences in 1905. A more detailed examination of the road to Standard Time is presented in author Clark Blaise’s Time Lord (2000). Between these two books we can ride a whale of a tale, in which prominent crusaders play benign versions of Captain Ahab, with far greater success than Herman Melville’s doomed protagonist in Moby Dick.

Sun Time: “God’s Time” Meets Sundial. Prerau divides the history of time’s intersection with humanity into four phases: (1) Sun Time; (2) Mean Time; (3) Standard Time; and (4) Daylight Saving Time. Sun Time is also known as God’s Time and/or Nature’s Time; the role humans played was simply that of passively measuring time. The latter trio involved humans creating new measures of time to meet the evolving needs of societies.

We begin with two ancient civilizations: Sumer, nestled between the Tigris and Euphrates Rivers (Mesopotamia then, Iraq today); and Egypt, whose ancient capital was Thebes, by the west bank of the Nile. Obelisks were erected to guide the activities of religious worship and government officials. At least 3,500 years ago, Egyptians subdivided time by using the sundial. Noon was marked by the longest shadow, vertically lined with the tip of the obelisk. This measure was essentially unchanged for 3,000 years. Later, Hipparchus (ca. 190-120 B.C.), the Greek astronomer, cartographer and mathematician, divided the Earth into 180 parallel horizontal lines (later, latitude) and 180 parallel vertical lines (later, longitude). These longitudinal lines became known as meridians, after the Latin meredies—midday—as along each meridian line the noon hour is the same.

Ca. 1270 marked the advent of the mechanical clock. In his book, The Measure of Reality, author Alfred W. Crosby writes that the division of time into units of one hour reflected a recognition that unlike days, which are bounded by the natural events of light and darkness, and unlike calendars, which are encrusted with customs and traditions—holidays—hours are an arbitrary duration and thus readily definable by utilitarian criteria. The ancients had thought of time as a continuous flow; the need for more precision led during the High Middle Ages to learning regard time as a series of discrete quanta. Public clocks used bells to guide urban dwellers, where most commerce flourished and thus were in need of regularity. The English word “clock” is derived from the French cloche and the German Glocke, for bell. The next step was the escapement, an oscillating mechanism for precise mechanical alternation between tick and tock. Crosby adds that in the 17th century, the final steps in fixing calendar time came with counting years, per the Jesuit scholar Dominic’s Petavius (B.C/A.D and C.E./B.C.E.), and migrating from the 4th century Julian to the 18th century Gregorian calendar.

The public clock, usually in a town square, first appeared in London in 1292, Paris in 1300 and Padua in 1344. A 14th century Cairene astronomer and mathematician, Abdul-Hassan al-Marrakushi, used trigonometry to create the mathematical 24-hour day, which by the end of the 15th century had spread throughout Europe. Until the 16th century, most clocks had one hand, striking the time by quarter-hour. Individual town times were called “apparent solar time.”

The oldest working clock is some 600 years old, an “astronomical clock” in Prague’s Old Town Square. It uniquely uses 24-hour time, and can still locate the Sun, Moon and stars; it is a collection of four distinct clock faces. One goes by Bohemian Time, used during the middle ages; a second face shows German Time, adopted in Europe in 1547, still in use today as Central European Time; a third face shows Ancient Babylonian Time, which divides daylight into twelve segments; the fourth face shows the Sun’s position in relation to Earth, day and night. (For these and other Times, see this website.)

Mean Time: Greenwich Melds Astronomers and Sailors. Navigation for thousands of years was by dead reckoning, using the stars. It was only by sighting stars that navigators could locate ships in terms of latitude (distance, north or south, from the equator) and longitude—distance, east or west, from a designated prime meridian. Mean Time was first used as a temporal yardstick in Geneva, in 1780; other Swiss towns followed suit. Greenwich Mean Time (GMT) was ultimately chosen by the British (rather than London) because the Greenwich observatory was used by the Astronomer Royal, a position established in 1675, to make accepted calculations. Setting up the system melded time and space in measurable distances and time zones.

By the late 19th century, 90 percent of the world’s shipping used the Greenwich prime meridian; the other 10 national prime meridians represented a mere 10 percent of global shipping traffic. Eight were centered on European cities (Paris, Berlin, Rome, Cadiz, Lisbon, Copenhagen, Stockholm and St. Petersburg), with Rio de Janeiro and Tokyo as outliers. Thus, Greenwich is situated at 0 degrees Longitude.

Standard Time: Railroad Timetables Defeat Farmer Stables. The first railroad time was London Mean Time, adopted in 1840 by Britain’s Great Western Railway. In 1848, Britain became the first entire country to adopt GMT. Its motive force was the dramatic increase in speeds of communication, via wire telegraph; and travel, via the steam engine. The Victorian Age was made possible by what Blaise calls the Age of Gauges, each of which is

. . . an intricate conversion device, a kind of translator between unspoken languages. Scales, thermometers, watches, fuel pumps . . . . Like crude computers, they monitor one set of operations and convert it to a different data flow—to time, to temperature, to volume, to cost, to profit, to depletion.

The dominant propulsion system on railway tracks was the locomotive, which could be steam-, electric-, or diesel-powered. On Oct. 6, 1829, Robert Stephenson’s “Rocket” steam locomotive, which incorporated myriad technical innovations, won a competition by drawing a 20-ton load 70 miles in 10 hours. Blaise notes that from the 1830s, rates of land/water travel increased geometrically—eventually, a hundredfold—what one historian called “a change in the rate of change.” Increasing speeds and distance covered gave birth to increasing travel confusion, as travelers saw their watches diverge more from local time.

In 1842, Toronto became the first city to draw its time computation by telegraph “magnetically signaled” from a nearby observatory; in 1848, Britain became the first country to put the entire country on one time signal, from the Greenwich Royal Observatory. In 1868 the Naval Observatory in Washington, D.C. followed suit for the entire U.S. As the industrial revolution spread throughout industry, the need for precise timing and convertible formats grew; the time-and-motion studies that drove Frederick Taylor’s “scientific management” of mass production led to explosions in capitalist innovation, albeit at a high cost in worker health and welfare.

In 1845, Sandford Fleming sailed from Liverpool to Newfoundland; the trip took 48 days. His return trip, in 1863, aboard the steamer Great Eastern, took 8 days. The impetus for finally ending the worldwide dominance of “God’s Time” was when Fleming missed a Bandoran, Ireland train in the summer of 1876, due to a misprint in the schedule, as to AM or PM.

Each railroad had its own timetable and choice of time to follow. A passenger taking the train from Pittsburgh to Buffalo had to figure out all relevant timetables. Trains originating in Pittsburgh ran on Philadelphia time, adjusting for the sundial position, its five degrees of longitude set Pittsburgh clocks 20 minutes behind Philadelphia’s. But the Pittsburgh to Buffalo train originated in Columbus, Ohio, another three degrees longitude west, making for 12 additional minutes earlier. Arriving in Buffalo, the hapless traveler faced three different time zones, as Buffalo had three railroads serving it, and they all ran on different local times. Wisconsin operated with 38 different local times. Travelers riding the rails from Maine to California faced more than 20 timepiece adjustments. At mid-century, America had 144 different local times.

All this changed on April 8, 1883, at the General Time Convention of the American Railroad Association; fittingly, the meeting was held in St. Louis, where six official railroad times were observed. A railroad man, William Allen, offered a division of what became, by 1912, the 48 contiguous states, into four time zones, beginning at Longitudes 75, 90, 105 and 120 degrees: Eastern, Central, Mountain and Pacific. Adoption would replace 50 railroad time standards then prevailing. At 2 AM, Sunday, November 18, 1883, America’s railways migrated to a unified continent-wide standard time; the 2 AM conversion time was chosen because it would be least disruptive, as passenger loads were lowest, and hence fewer trains ran. Blaise notes that within days—astonishing given limited communications of the day—70 percent of schools, courts, and local governments adopted Standard Time. But the federal government did not accept the change until—NOT a misprint—1918.

The Oct. 1-22, 1884 Washington. D.C. Prime Meridian Conference (PMC) divided the 24-hour day into 24 time zones, each of roughly 1,000-miles distance; this enabled the 360-degree circumference of the Earth to be divided in 15-degree segments. Also defined then was the International Dateline, the universal day that reset the calendar, and the 24-hour clock. Solar time travelled from east to west, covering 12.5 miles per minute.

Wireless telegraphy and undersea cables greatly increased the need to track global time regularity. The first transatlantic cable linking Newfoundland and Britain operated briefly in 1856; two more durable cables were laid in 1866. Fleming’s crowning achievement came with the opening of the worldwide transpacific cable. In 1902 Fleming sent a pair of messages from Ottawa to Sydney, Australia, one eastward via Newfoundland, with intermediate routing via London, Gibraltar, Malta, Egypt, and India; and one westward via Vancouver, transiting to Sydney via Fiji. Australia replied to each message. Total transit times: eight hours. Blaise notes that the entire routing went through British territory—either Commonwealth countries of imperial colonies. (The apogee of the Empire upon which the sun never set was reached upon the British victory at Omdurman, Sudan, Sept. 1-2, 1898; one participant was a subaltern named Winston Spencer Churchill.)

Sunlight Time: DST’s Temporal Twists and Turns. Prerau marks 1444 as the first time that a clock was advanced one hour—not to save daylight, but to save the Swiss town of Basel. Invaders planned to attack when the town clock struck noon. The tower watchman learned of imminent attack and, unable to notify defenders in the minutes that remained, he manually advanced the clock by one hour. When the attackers heard only one bell rather than twelve, they were confused. Defenders rallied and drove them out of town. It was to be 472 years before Daylight Saving Time made its global debut, and it took a world war to force its adoption.

Having publicly rhapsodized over the joys of daylight in London (1757) and then while serving as an envoy in Paris (1784), Benjamin Franklin became the first to propose government action to address the matter. He did not, however, seek resetting of clocks. Rather, he proposed that the government impose a tax on shuttered windows when there is natural light outside; limit candle supplies; stop coaches after sunset; and ring all church bells upon first light, to wake everyone up.

Yet two problems remained unresolved: the rotation of the Earth’s axis, creating a series of sunrises and sunsets; and the 23.5-degree tilt of the Earth’s rotation, which alters daily the local time of sunrises and sunsets. Such seasonal variation gives us the winter and summer solstices, for the year’s shortest and longest days; and the vernal and autumnal equinoxes, when days and nights are 12 hours each, with local times varying daily between those dates.

The idea for seasonally-altered DST originated with a British MP, William Willett, whilst riding his horse one summer morning in countryside south of London; he rode alone, near his fellow townsfolk sleeping in Chislehurst. He thought if workers rose an hour earlier, they’d make use of natural light instead of working late in artificial light. Opposing the idea: farmers who needed to wait until after morning dew in order to harvest wheat; plus scientists and astronomers who rejected tampering with astronomical time. He brought his idea to Parliament in 1907, but it died there, as did subsequent efforts. When the House of Commons did pass a couple bills, each time the prime minster, Herbert Asquith, spoke against them. Willett died March 4, 1915, his dream unfulfilled.

Enter World War I. By then, World War I was in full swing. As the conflict widened and casualties mounted, wartime necessity required reducing unnecessary energy consumption, and keeping lights off an extra hour reduced demand for energy. First to adopt DST was Wilhelmine Germany, on April 6, 1916; other continental European nations rapidly followed suit. With Asquith ending his opposition to DST, it took Parliament all of six weeks to pass a DST bill, on May 15, 1916; the King consented two days later, and DST went into effect 2 AM Sunday, May 21. The Summer Time Act of 1916 had a provision authorizing renewal votes, and in 1917 renewal was made automatic for the duration of the War. Upon the Great War’s end (Nov. 11, 1918), when the Summer Time Act came up for renewal in 1919, it was dropped.

America was next. Two cities, Detroit (1907) and Cleveland (1909) were unhappy with being cast into the Central Time zone. They sought to have their cities included in the Eastern zone. Doing so would give their residents an extra hour of daylight year round. The Cleveland City

Council adopted Eastern Standard Time in 1914, with Detroit’s City Council following suit in 1915.

The first group to propose national adoption of DST was the National Daylight Association of Cincinnati. They approached President William Howard Taft two months after Taft entered the Oval Office; Taft and his Cabinet suggested that the group start locally, and later go to Congress.

Corporations and labor unions, often antagonists, united to push for DST. Railroads were content with Standard Time, and adamantly opposed imposition of the added complexity DST would add to their timetables. One argument they advanced was that there were 1,698,818 railroad clocks and watches that would have to be adjusted.

Things were in stasis until America entered the War on April 6, 1917. Congress stepped into the breach, but it was not until March 19, 1918 that President Wilson signed the Standard Time Act of 1918, which included the Daylight Saving Time Act; DST began on March 31, to run April through October. Detroit adopted Central Time for the months of DST, giving it two hours of added sunlight, but Cleveland, closer to the Eastern Time zone, did not. Upon the War’s end, immediately Congress sought to repeal DST. Twice President Wilson vetoed the bills, but the third time proved a charm. Passed by large majorities in both Houses, the second presidential veto was overridden, and on Aug. 20, 1919 Wilson signed the DST repeal bill.

Yet DST remained a live political issue: On May 23, 1922, a Washington, D.C. radio station broadcast the first-ever nationally broadcast political debate on DST. The audience decided who won (the author does not say).

But cities and states were still free to adopt local DST. In 1920, only two states, New York and Massachusetts, elected to keep DST. (In 1921, New York repealed statewide DST, but New York City kept it.) In 1926 the U.S. Supreme Court chimed in, per Justice Oliver Wendell Holmes, dismissing a challenge to the constitutionality of the Massachusetts DST law. The aptly-named Connecticut town of Hazardville marked 1927 by adopting three local time zones: churches and shops adopted full DST; farmers kept EST; while mills, which dealt with both town and country, chose 30-minute DST.

South of Baltimore, where rural interests dominated until recent times, only Raleigh, North Carolina adopted DST, and only for four days in 1932. But by the late 1930s, 15 states with one-quarter of the population observed DST. The newly-formed (1934) Federal Communications Commission ruled that in areas where multiple radio stations shared spectrum frequency bands, if any local station followed Standard Time, all had to do so. When in Sept. 1938 a major (cat 3) hurricane rocketed up the east coast, slamming hardest into the northeast, the prevalence of DST aided recovery efforts.

During the interwar period (1919-1939), most European countries abandoned DST. Notable exceptions were Britain, which enacted permanent summer DST in 1925, and the Soviet Union, which adopted year-round DST in 1930.

Instant Replay: World War II. During World War II, the identical arguments that prevailed a quarter-century ago again did so, and DST was widely adopted. Britain extended its normal Summer Time, eventually running from late February to early November. After the war it reverted to peacetime DST, but the severe winter of 1947 forced adoption of emergency winter DST; in 1948 it reverted to Summer Time. America waited until after Pearl Harbor to return to DST; on Feb. 9, 1942 the country went on year-round DST, to be terminated six months after the War ended. A few localities did not follow suit. Congress decided not to wait for the six-month expiration, ending nationwide DST four weeks after V-J Day, on Sept. 30, 1945. But by 1947, 50 million Americans, about one-third the population, continued to observe DST.

Postwar Travails. The postwar period descended into what Time Magazine called, in 1963, “a chaos of clocks.” In 1964, DST began on 19 different dates and ended on 14 different dates. One year Iowa was saddled with 23 combinations of standard and DST; Hopkinton banks opened on DST and closed on standard time. Intercity bus service, at one point, took passengers through seven time zones--one change every eight minutes—during a 35-mile ride from Steubenville, Ohio to Moundsville, West Virginia! Rural dominates in northern Idaho took time variance to its logical end-point: observing—NOT making this up—door-to-door variances.

In the wake of the Time article, a movement for a nationwide return to summer DST gathered momentum, and in 1966 the Uniform Time Act of 1966 went into effect, but with a provision allowing states to exempt themselves upon passage of a state law. By 1971, four states—Arizona, Indiana, Hawaii and Michigan—had passed such laws. Indiana’s decision to allow two western areas to use CST, and the rest of the state to use EST, and also use DST in a single zone led Congress in 1972 to pass a specific exemption for such states. Eleven other states had multiple time zones, but none enacted partial DST zones.

The year 1973 was a genuine annus horribilis: the first Arab oil embargo, the summer Watergate hearings, resignation of the vice-president over corruption, and the firing of a special prosecutor investigating the president (only to be replaced by a new one). The term “energy crisis” entered the political lexicon. Once again, to conserve energy, Congress acted. The Emergency Daylight Saving Time Energy Conservation Act mandated a full two-year DST, from Jan. 1974 through Oct. 1975.

In the first two-weeks of Winter DST, schoolchildren were killed in the now-darker morning by cars in six states. But the killer of year-round DST was Florida, where over several weeks (presumably more than two) eight kids were killed, versus two during the same period in 1973. That did it. Photos of dead children aired on national television proved anew that pictures are worth a thousand words; there were no photos of kids who would have been hit by cars given darker afternoons, to provide a competing narrative.

Congress repealed year-round DST, with Standard Time resuming Oct. 27, 1974, and DST resuming Feb. 23, 1975. The Dept. of Transportation conducted a study that found three modest benefits from DST: energy conservation, traffic safety and crime reduction. Upon expiration of the 1973 bill, the nation returned to the 1966 UTA rules. A renewed push for longer DST began in 1984, driven by fast food businesses and recreational interests. The result was inclusion of a three-week extension of the advent of DST, to early April in the Federal Fire Prevention and Control Act of 1986.

21st Century Revival. In 2005, Congress passed a second extension of DST. With the Energy Policy Act of 2005, and energy conservation a major goal, the Act added five weeks to DST: four in March and one in November—the latter giving Halloween merchants and trick-or-treaters the benefits of twilight to better ward off evil spirits of darkness.

American DST now runs eight months, from early March though early November. Amtrak pauses its trains for one hour in the fall changeover, as trains cannot leave the station before their published scheduled departure; when DST resumes, trains depart at 2 AM Sunday, and try to make up lost time en route. Overseas, Continental Europe adopted uniform start and end times for DST in 1996, with Britain joining in 2002.

Sunlight Forever: Permanent DST? Several states, including California and Florida, have passed year-round DST, to go into effect if Congress adopts nationwide DST. On March 15, 2022, by unanimous voice vote the Senate passed the Sunshine Protection Act. To allow the railroads to adjust their timetables, the bill had set November 2023 as the date full DST was to be adopted—the clocks would not have been set back. Senators cited the inconvenience of changing clocks twice annually. But the DST bill died in the House.

Sen. Marco Rubio reintroduced the bill in the 118th Congress, on March 3, 2023; with Republicans now in control of the House, a companion bill was introduced by Rep. Vern Buchanan (R-FL), a move blocked by former House Speaker Nancy Pelosi in the 117th. The new bill exempts Arizona, Hawaii, Puerto Rico, the Virgin Islands, the northern Marianas Islands, Guam, and American Samoa.If the new Congress adopts year-round DST, the earliest implementation would be November 2024; if done in the second year of the new Congress, implementation likely would be in November 2025.

Millennium Extravaganza. Worldwide time zones made possible a singular global event: the celebrations that collectively marked Millennium New Year, January 1, 2000. (Calendar purists complained that the true Millennium milestone would be January 1, 2001; the calendar went from 1 B.C. to 1 A.D.—there was no Calendar Year 0.)

Lucky viewers were able to watch celebrations serially as the year moved westward. The common denominator was Universal Coordinated Time (UTC), described as

Coordinated Universal Time—is the 24-hour time standard used as a basis for civil time today. All time zones are defined by their offset from UTC. The offset is expressed as either UTC- or UTC+ and the number of hours and minutes.

Primarily, UTC is based on mean solar time at the prime meridian running through Greenwich, UK. For every 15 degrees of longitude east or west, mean solar time changes by 1 hour. Two time components are added together to translate mean solar time to Coordinated Universal Time (UTC): International Atomic Time (TAI) measured by atomic clocks and Universal Time (UT1), the actual length of a day on Earth.

In theory, the UTC offsets countries use should reflect the local mean solar time. However, many time zone boundaries are distorted by geographical and political factors.

Claimants for the first to reach 2000 were legion, sundry islands located near the International Dateline (IDL), at UTC+14; the U.S. nuclear attack submarine Topeka (SSN 754) stationed herself at 400 feet depth underneath the intersection of the IDL and the equator. The first major industrial nation to cross the mark was New Zealand, at UTC+13. The last place to cross into the 21st century—uncontested—was Samoa, UCC-11. For those who arose at the proper hours, it was possible (the author did so) to observe myriad celebrations around the globe. It was an impressive and exciting demonstration of the interlinked wonders of communications and satellite broadcast technologies. displayed on viewers’ television sets.

Bottom (Time) Line. The 5,500 years since Egyptians first used the sundial to divide time into artificial segments have seen the growing need for precision—now, nano-precision. By 2005 much of the world had reached worldwide time-zone equilibrium, a process that formally began in 1883. Time precision grows of necessity, as billions of computers, phones and robots proliferate globally. The modern cesium-ion atomic clock carries precision to a measurement loss of one second every 10,000 years by using 20 billion pulses per second.

But the drive to make DST countrywide hinges not on the need for precision, but on desires for convenience and emotional equilibrium. The year-round DST bill’s chances in the 118th Congress may hinge on whether people in the fall hate four months of afternoon darkness more than they love an extra hour’s pre-dawn slumber.

John Wohlstetter is author of Sleepwalking With the Bomb (Discovery Institute Press, 2d. ed. 2014)