How did people measure a year and specifically how did the fix the time for a day?
World has been following three systems for calendar.
1.Solar,based on the movement of the Sun,called the Suryamanasa in Hinduism.
2.Lunar,based on the movement of the Moon, Chaandra Manasa.
In India both are used.
3.There is also the practice of using both together Luni Solar system.
This is practiced by the Chinese.
How is the beginning of a day calculated?
Today,the world follows midnight to midnight as one day.
The origin of this is lost .
Historically, there seems to have been four norms to decide one day.
That is taking 5.30 am as the Sun rises in India,12 midnight has been taken as the beginning of a new day.
One must remember that Britain was ruling the world,colonising the countries.
‘There are four main views of when a day begins and ends. These are 1) midnight-to-midnight 2) evening-to-evening 3) dawn-to-dawn and 4) dawn-to-sunset.
Midnight is the popular transitional point that separates one day from another, and is used in civil time throughout the world. However as this practice does not appear to have a Biblical basis, we will only consider the evening-to-evening, dawn-to-dawn and dawn-to-sunset as the possible Biblical start and end of each day…
Jewish Calendar Date
When G‑d created time, He first created night and then day. Therefore, a Jewish calendar date begins with the night beforehand. While a day in the secular calendar begins and ends at midnight, a Jewish day goes from nightfall to nightfall. Shabbat begins on Friday night, and a yahrtzeit lamp is kindled the evening before the yahrtzeit (anniversary of a person’s passing), before nightfall. If the 10th of Iyar falls on a Wednesday, and a child is born Wednesday night after dark, the child’s birthday is the 11th of Iyar.
On those dates wherein certain activities are restricted — such as working on Shabbat or major holidays — the restrictions go into effect the night beforehand.
[Most fast days begin at dawn (“alot hashachar“), and as such are an exception to this rule. Yom Kippur and Tisha b’Av, however, do begin at nightfall of the previous night.]
Though the day and its restrictions begin the night beforehand, many obligations associated with specific calendar dates — such as hearing the shofar on Rosh Hashanah, taking the Four Species on Sukkot, or hearing the daytime reading of the Megillah on Purim — must be performed during daylight hours only.‘
‘In Islam, the night precedes the day.
The new hijri date begins with the setting of sun. Hence for e.g. once the sun sets after the 11th day in Ramadhaan, the 12th has already begun.
So, if today is Thursday 3:15 pm then Maghrib begins at 5:00 pm then know from the moment Maghrib time begins on that day, Friday begins.
The Islamic cycle of a day begins with the setting, not the rising of the sun. In countries such as Saudi Arabia, where the Islamic calendar alone is norm, when someone is speaking about going out on Friday night, he means the night that comes before the “day” of Friday.
According to The Bible,
‘Sam 19:11 Saul also sent messengers to David’s house to watch him and to kill him in the morning. And Michal, David’s wife, told him, saying, “If you do not save your life tonight, tomorrow you will be killed.”
Michal made a distinction between “tonight” and “tomorrow”. ‘Tonight’ was not the same as ‘tomorrow’. ‘Tomorrow’ was to come after ‘tonight’, and when it came in the morning, Saul sent to kill David as He had planned. The day did not begin at evening, but in the morning.
Jonah 4:7 But as morning dawned the next day [Elohim] prepared a worm, and it so damaged the plant that it withered.
When did the worm appear? Answer: as morning dawned the next day.
Mark 16:2 Very early in the morning, on the first day of the week, they came to the tomb when the sun had risen.
Luke 24:1 Now on the first day of the week, very early in the morning, they, and certain other women with them, came to the tomb bringing the spices which they had prepared.
Matt 28:1 Now after the Sabbath, as the first day of the week began to dawn, Mary Magdalene and the other Mary came to see the tomb.
Combining all three accounts, it is clear that the women went to the tomb early in the morning, at dawn on the first day of the week. The evangels did not say at evening on the previous day. However having the mindset (without proof) that Sabbath ends at sunset, some persons try to twist what is clearly a dawn visit into an evening visit so as to make this account fit in with their erroneous theory that Sabbath ends at sunset.’
‘position set forth in this study is that the Scripture teaches the terminus a quo (i.e. the start) of a new day to be at morning rather than at evening. The following evidence from Scripture is brought forth in order to demonstrate that a new day begins at morning.
1. When expressions like “tomorrow”, “that night”, “the next day”, or “the same day” are used in Scripture, the context in certain texts indicates that the night is a continuation of “the same day” that preceded it (and not the beginning of a new day). Whereas the following morning is distinguished from the previous night by being designated as “tomorrow” or as “the next day.”
a. Genesis 19:33-35
All the incestuous events of Gen. 19:33 occur on “that night.” However, the recounting of the events of the previous night actually occurred “on the morrow” (Gen. 19:34). Also note that the dialogue between the daughters of Lot “on the morrow” (Gen. 19:34) occurred before nightfall (“that night also“, Gen. 19:35), and yet what occurred the night before (Gen. 19:33) and what occurred the day after (before nightfall) are reckoned as two different days (“the morrow“, Gen. 19:34). This chain of events can only be reckoned as two separate days if the following morning begins a new day. If the previous evening begins a new day (as the evening view affirms), then one could not refer to the following morning and afternoon (before night) as “the morrow.” For the previous night, the next morning, and the next afternoon (before night) would all be the same day and not two separate days.
b. Exodus 16:23-25
This passage is significant for it refers to the Sabbath. In preparing for the Sabbath, God commanded Israel to gather twice as much manna on the morning of the sixth day because they were not to gather manna at all on the seventh day (Ex. 16:22, 26). On the sixth day, Moses declared, “Tomorrow is the rest of the holy sabbath unto the LORD” (Ex. 16:23). When is “tomorrow“? That same evening or the following morning? The text makes it clear that they were to bake and to boil all that they needed for food on that same day (the sixth day), and the manna they did not need for that day would be preserved from spoiling until the next morning (unlike other days, cf. Ex. 16:19-20). Moses states what is to be done with the manna that did not spoil on the morning of the seventh day: “Eat that today, for today is a sabbath unto the LORD; today ye shall not find it in the field” (Ex. 16:25). The text does not indicate that leftover manna bred worms or became spoiled immediately before sunset on the sixth day (which would be the beginning of a new day according to the evening view), but rather that all leftover manna became spoiled before morning. Why? Because morning was the beginning of a new day. It is also significant to note that the text does not associate the start of the Sabbath with the evening, but rather Moses declared, “Tomorrow is the rest of the holy sabbath” (Ex. 16:23). The “tomorrow” when the Sabbath began was the following morning (Ex. 16:23). On the morning of the seventh day Moses stated, “Today is a sabbath unto the LORD” (16:25). There is no indication that the Sabbath began the night before. Is there even one example in Scripture where “tomorrow” refers to the evening that immediately follows the morning and afternoon that precedes it? I have not yet found such a passage.