Time and time zones

Do you have the time please?  It depends on your time system. 

How did people tell the time?  Although the ancients had water  clocks, candle clocks, and even primitive  mechanical clocks, the Tanach and  Chazal seemed to rely almost exclusively  on observing the sun.

For example, when Yeshayahu  informed King Chizkiyahu that he would  survive a fatal illness and live another  fifteen years, Yeshayahu concluded:  “And this is the sign from Hashem  for you that Hashem will do this thing  that He spoke. Behold, I will turn back  the shade of the steps that descended the  steps of Achaz in the sun back ten steps,  and the shade will go back ten steps on  the steps that it descended” (Yeshayahu  38:7, 8).

Rashi explains that the steps of Achaz  were “sort of steps made opposite the sun  to detect the hours of day with them, like  a horologion (a timepiece) that craftsmen  make.”

However, the Gemara generally  ignores sundials and relies on detecting  the time directly from the sun; for  example, various sugyos discuss people  determining the time from the sun’s  height.

One of the rare places where Chazal  mention another way of detecting the  time is where the Zohar (Bereishis 92b)  describes a water clock:

“R. Abba traveled with his son R.  Yaakov from Trunia to Teveria to visit  his father-in-law, and on the way they  spent the night in the village Tarsha.  Before going to sleep, R. Abba asked the  baal bayis, ‘Do you have a chicken?’  “’What for?’ asked the baal bayis.  “’I wish to wake up at midnight,’  replied R. Abba, ‘and I need a chicken  to waken me.’  “’There is no need,’ said the baal  bayis. ‘Next to my bed is a scale. On one  of its pans I place a weight and on the  other I put a container of water with a  hole. By midnight the container empties  and the opposing weight falls to the fl oor  making a noise in the whole house.’”

Why do we split the day into 24  hours in the first place? Why not 20 or  26 hours? After all, an Egyptian sundial  from about 3,500 years ago split daylight  into ten hours instead of twelve.

Strangely, the Tanach does not  mention the concept of 24 hours at all,  and it appears for the first time in the  Gemara and Medrash. For example, the  Gemara (Sandhedrin 38b) states that,  “The day has twelve hours.”

The Chazon Ish (Yoreh Dei’ah 85:74)  initially writes that hours are not a mere  human convention but the intent of the  Torah in order to perform certain mitzvos.  For example, beis din need to ask  witnesses what hour of the day they saw  something happen. Then he concludes,  “And all this requires investigation and  we cannot reach a conclusion about it.”

On the other hand, the Urim veTumim  (30:13), the Ohr Sameach (Eidus 1:4)  and the Chazon Ish elsewhere (Orach  Chayim 13, letter 1) write that dividing  the day into twelve hours is a human  convention and not something decreed  by the Torah or by Chazal. 

Although the Gemara does not say  so explicitly, most poskim hold that the  hours that determine mitzvos like Kerias  Shema fluctuate according to the length  of the day. Thus, an hour is one twelth of  the day and the longer the day the longer  its hours, so that we read Kerias Shema  later in midsummer than in midwinter.

Rambam is one of the earliest Rishonim  to mention this vital point (Peirush  haMishnayos Berachos 1:2).  A minority of Rishonim and  Acharonim hold that Chazal’s hours are  the same as the unvarying hours we use  today, and have the same length the whole  year. According to this opinion, the last  time to say Krias Shema is 9:00 a.m. the  whole year round. Although Rav Eliezer  of Munkach rules like this opinion lekula  in his Minchas Eliezer, most poskim  disagree and the Igros Moshe rules that  one does not have to be concerned about  it even lechumra. 

A strange system widespread  throughout the Ottoman Empire and  still used in Yerushalayim today, was  “Moslem time” where people set their  clocks at 12 every sunset. Because days  are usually shorter or longer than their  preceding day, people had to reset their  clocks at sunset every day. With this  system, by midnight it was only six o  clock.

A convenient feature of the Moslem  clock was that every sunset muezzins  (people who call Moslems to prayer)  yelled out from every minaret in town so  people didn’t even have to look out for  the sun to know the time.

As one rav wrote: “(Immediately)  after sunset, the Arabs on duty shout and  scream so that their voice is heard in the  whole town at 12-o-clock, and so it is  every day. In the Diaspora people do not  understand this… But, the truth is that  the national custom here, instituted by  the king and his ministers, is to be careful  to begin night on clocks everywhere  at the same time, to begin the count in  the evening as above – the first hour…  And if the day alters a few minutes,  whether longer or shorter, people set  their timepieces later or earlier… and  synchronize it with the shouting at the  12th hour.”

In its heyday, Moslem time was  popular all the way from Greece to  Morocco, but after the British conquered  Palestine it gradually dwindled until  today when it is only used by some  Arabs and by some Yerushalayim Jews  who prefer it because it starts at sunset in  accordance with the verse, “And it was  evening and it was morning.”

Some rabbonim, including Rav  Shlomo Alfandri (chief rabbi of  Damascus and Istanbul who spent the  end of his life in Eretz Yisroel) went as  far as to say that the modern time system  that contradicts our heritage by starting  the day at midnight is a conjunct of  idolatry.

The catch with Moslem time was that  many poskim held that halachic sunset  was a few minutes earlier, probably  because they held that halachic sunset is  determined by its visual sighting, while  the Moslems went according to the  earlier sunset at sea level.

Thus Rav Yehuda of Ayash writes,  “My teacher said that when their caller  cries out close to dark… it is already half  way through dusk.” 

In the past, every town reckoned  its time according to local noon and it  bothered no one. Who  cared what was going  on over the next hill!

Things remained  unchanged even after  the invention of reliable  clocks. For centuries,  people happily reset  their unreliable clocks  by the midday sun.  Then, in the 1840s,  England constructed a  network of telegraphs  that united the  country, providing  instantaneous  communication on  an ongoing basis. For  the first time, people began realizing  that everything was out of sync. To  make things worse, entrepreneurs were  developing nationwide railroads and  people would not be happy if a train from  a distant town chugged in ten minutes  late.

In 5607/1847 the Liverpool and  Manchester Railway created their own  standard time for the whole of England,  and within eight years it was being  used by 98% of English public clocks.  Railway men began pressing parliament  to formalize this arrangement by law,  but, like most innovations, this one too  ran into resistance. As one newspaper  declared: “Rally around Old Time with  the determination to agitate, and if needs  be, to resist this arbitrary aggression.  Let our rallying cry be: ‘The Sun or the  Railway!”

In 5611/1851, Sir George Biddel Airy,  the British Astronomer Royal (chief  astronomer) established Greenwich as  the Prime Meridian – the official center  of the world where east meets west.

According to this arrangement, every  spot in the world would be measured  east or west of an imaginary line running  from the north to south pole through  Greenwich near London. 180 degrees  away at the other side of the world would  be the international date line.

As Greenwich is a big place, Airy  plonked his Meridian line on the  crosshairs of a telescope he had built a  year earlier. If you want to straddle two  hemispheres at once, go to Greenwich  and stand over its Meridian line that  splits east from west.

Greenwich time took over. For a while,  some clocks had two minute hands, one  to mark local time and a second one for  Greenwich time, but by 5640/1880 it  became legal time throughout England.  Four years later the Greenwich  Meridian line was internationally  formalized when U.S. President Chester  A. Arthur organized the International  Meridian Conference in Washington  D.C. attended by 41 delegates from 25  nations.

The chief conclusions were 1) “That  it is the opinion of this Congress that  it is desirable to adopt a single prime  meridian for all nations, in place of the  multiplicity of initial meridians which  now exist. 2) That the Conference  proposes… adoption of the meridian  passing through the centre of the transit  instrument (telescope) at the Observatory  of Greenwich as the initial meridian for  longitude.”

However, the Greenwich Meridian  was chiefly for use at sea. The resolution  specifically stated that it “shall not  interfere with the use of local or standard  time where desirable.”

For England, that  only has one time  zone, this was not a  problem, but what  about the USA that  stretches through a  number of time zones?  How did Americans  keep their trains  running on time? For  a while, USA railroad  companies ran on their  own times and some  stations kept several  clocks running to show  them all. The problem  was resolved on the  “Day of Two Noons” in 5643/1883,  when railroads reset their clocks to four  standard time zones at noon, and most of  the USA soon followed suit.

Since the 1920s, the whole world has  been using time zones based on splitting  the world into 24 segments of 15 degrees  each, each one an hour apart from the  next.

Now at last, when someone asks  you the time you can give an accurate,  unambiguous reply.

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