It's evening or day. Morning day evening night by hour

Day is an ambiguous concept. “Day” can be understood as the morning of the next day or as lunch time, that is, noon. In the usual sense, noon begins at 12 o’clock and ends at 5 pm; at this time it is not even recommended to sunbathe on hot days. But the beginning of a new day varies within different limits for everyone.

What time do you like to start your day? On weekdays, little depends on your desire, because if you need to get up at 6, despite being sleepy, you will do it. What about the weekend? Here, most likely, the day starts at different times, depending on when you wake up.

In fact, getting up at 6-8 am is one of the best ways to start the day. According to doctors, people who get up at this time feel the maximum surge of strength and energy, which affects, first of all, the efficiency of the coming day and the health of the entire body. But it is also important to take into account that sleep should ideally last at least 8 hours, so you will have to go to bed much earlier. Therefore, if you cannot get up before 9 am, then do not be upset, because this also has its advantages. For example, you go to bed around 12 o’clock at night, which means you have time to do a lot of important things in the evening, because most of the big ideas come to some people at this time of day.

Nowadays, getting up, especially on weekends, at a certain time is quite difficult, especially since we must not forget that there are people who are night owls who can only fall asleep after 12 o’clock at night. Bustle, a large number of tasks, a tendency to irregular working hours, unstable weather - all this leads to the fact that we cannot always control the beginning of our own day. Of course, it is best to make it a rule not to wake up later than 11-12 hours, since doctors say that the chances of leading a healthy and active lifestyle with this regime are much less. There are many techniques that allow you to stabilize the start time of your day. For example, you can train yourself to fall asleep and wake up at the same time, at first, using an alarm clock.

A fairly pressing question in this topic is “What is the best way to start your day?” First of all, I would like to note that, despite all the rules, it is best to start your day with a good night's sleep, because this is the most important thing for the successful implementation of further affairs. So, if this means sacrificing your evening activities, rest assured that it will be worth it. Also an integral component of a successful day is morning exercise. If you have the opportunity to go for a run in the morning, you will fill your body with even more energy and alertness.

It is necessary to start your day with positive emotions, because, as you know, we ourselves model our reality. But doing this is not as easy as it might seem at first glance. We are all human, and we tend to fall asleep with numerous worries about this or that situation, and if there is still a depressive state, then in the morning you can generally wake up with a “heavy head.” If you wake up in a bad mood, then the whole day will go awry. There is a unique way to help you get into a good mood and contribute to a favorable day. Firstly, before you go to bed, try to think about the problems and affairs that have accumulated during the day, so that you can go to bed, as they say, with an “empty head.” Closing your eyes, imagine in great detail your tomorrow the way you would like it to be. And that’s it, after that you can fall asleep. This technique does not always work the first time; it is very important to be emotionally attuned at the moment of visualization.

Finally, I would like to give an example from personal experience. I used to have difficulty waking up on weekends around 11-12, and sometimes later. Recently I began to train myself to get up no later than 10, I do exercises regularly and try to greet the beginning of the day in a good mood. Surprisingly, much more strength and desire to do something appeared. Have a nice day!

Comparison of the duration of sidereal (2) and solar (3) days when the directions of orbital and proper rotation coincide

The length of a day on a planet depends on the angular speed of its own rotation. In astronomy, there are several types of days, depending on the reference system. If you choose a distant star as the reference point for rotation, then, unlike the central star of the planetary system, such days will have a different duration. For example, on Earth there is a distinction between the average solar day (24 hours) and the sidereal or sidereal day (approximately 23 hours 56 minutes 4 seconds). They are not equal to each other because, due to the orbital motion of the Earth around the Sun, for an observer located on the surface of the Earth, the Sun is displaced against the background of distant stars.

A true solar day is the period of time between the two upper culminations (successive passages of the center of the Sun through the southern part of the meridian (for the northern hemisphere); in other words, the time between two true noons); the beginning of this day is taken to be the moment the center of the Sun passes through the southern part of the meridian; The hour angle of the center of the Sun is called true time (see Equation of Time). True solar days are longer than sidereal days and their duration varies throughout the year, which occurs from the inclination of the ecliptic to the equatorial plane and from the uneven movement of the Earth around the Sun.

International System of Units (SI)

The unit of measurement of time - day (Russian designation: day; international: d) is one of the non-system units of measurement and is not included in the SI. However, in the Russian Federation it is approved for use without limitation of validity period with the scope of application “all areas”. In this case, 1 day is taken to be equal to exactly 86,400 seconds. In the SI, a second is defined as 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom. Accordingly, the definition of a day in SI can be considered 794,243,384,928,000 such periods.

In astronomy, a day defined in SI seconds is called a Julian day.

The average solar day does not contain an integer number of seconds (for example, their duration at epoch 2000.0 was equal to 86400.002 s), and the duration of the average solar day is also variable due to the secular change in the angular velocity of the Earth's rotation (see).

Cultural boundaries of the day

For most diurnal animals, the day naturally begins at dawn and ends at sunset. Man, with his cultural traditions and scientific knowledge, has formed his own ideas about the time of the beginning of the day and dividing them into characteristic periods.

Ancient man was guided by the calculation of time by day or night. The earliest mention of the day as day and night connected together is found in Homer, and the day in his works began at dawn. In Ancient Rus', until the 13th century, “days” were not used as a unit of time. Old Russian chroniclers counted time in days from dawn to dawn.

• 0 hours: 19-24 time zones;
• 6 hours: 13-18 time zones;
• 12 hours: 7-12 time zones;
• 18 hours: 1-6 time zones.

Thus, for example, in European countries, the meteorological day begins at 18:00 (UTC) - at this time the results of the day are summed up, average and extreme values ​​of air temperature and other meteorological parameters are calculated. If the 1st time zone in the presented list is UTC+1, then we get that the meteorological day in a particular place can begin in the range from 19:00 to 24:00 official local time. In Russia, the time of several time zones is used, so each region has its own meteorological day limit (UTC time).

Special agreements related to the day

Temporary passes, etc. may expire at midnight. However, if the service provider's shift schedule (for example, public transport) covers, for example, the period from 6:00 pm to 1:00 am the next day (which may also be noted as 25:00), then the last hour can legitimately be considered part of the previous day. For example, the validity of monthly travel tickets on a city bus or trolleybus in Russia on the 1st day of the next month does not expire until the end of the work shift of public transport personnel, if its start fell on the previous day. For "Nederlandse Spoorwegen" (Dutch railways) a daily ticket is valid for 28 hours, from 0:00 to 28:00 (that is, 4:00 of the next day). London Regional Transport passes expire at 4:30 am on the day following their activation date.

Division of the day

The number of parts into which the day was divided, or night and day separately, depended on the degree of development of a given people and increased gradually with the development of mankind. Most of the peoples of the New World divided the day into only four parts, corresponding to sunrise, the highest point of its daily journey, sunset and, finally, the middle of the night. According to the traveler Gorrebou, who described Iceland in the mid-18th century, the Icelanders divided the day into 10 parts. The Arabs distinguished only the sunrise, its rise and fall, sunset, twilight, night, the first crow of a rooster and dawn. However, among some formerly uncivilized peoples, a comparatively precise division of the day could be found, as, for example, among the natives of the Society Islands, who in Cook's time had a division of the day into 18 parts, the length of which was, however, unequal; the shortest periods of time corresponded to morning and evening, the longest - midnight and noon.

In Babylon there was also a 12-hour division of day and night. According to Herodotus’ “History” (II, 109), the Greeks adopted this system from the Babylonians, and later, probably from the Egyptians or Greeks, the Romans adopted it. For example, in winter the duration of the “day hour” in Rome was about 45 minutes.

Divided into 12 main parts

Divided into 30 main parts

Division into 22 main parts

Divided into 10 main parts

To find out the length of the day before the era of the appearance of corals, scientists had to resort to the help of blue-green algae. Since 1998, Chinese researchers Zhu Shixing, Huang Xueguang and Xin Houtian have analyzed more than 500 1.3-billion-year-old stromatolite fossils that once grew near the equator and are buried in the Yanshan Mountains. Blue-green algae react to the change in light and dark times of day by the direction of their growth and depth of color: during the day they are colored in light colors and grow vertically, at night they are dark in color and grow horizontally. Based on the appearance of these organisms, taking into account their growth rate and the accumulated scientific data on geology and climatology, it was possible to determine the annual, monthly and daily growth rhythms of blue-green algae. According to the results obtained, scientists concluded that 1.3 billion years ago (in the Precambrian era), the earth's day lasted 14.91-16.05 hours, and the year consisted of 546-588 days.

There are also opponents to this assessment, pointing out that research data on ancient tidal deposits, tidalites, contradict it.

Change in the length of the day from 1974 to 2015 (vertical - scale in milliseconds)

In addition to changes in the speed of rotation of the Earth over a long period of time (and the resulting change in the length of the day), from day to day there are minor changes in the speed of rotation of the planet associated with the distribution of masses, for example, due to a decrease in the volume of the world's oceans or atmosphere due to fluctuations in their average temperature . When the world's oceans or atmosphere cool, the Earth rotates faster (and vice versa), as a result the law of conservation of angular momentum applies. Also, changes in the average length of the day can be caused by geological events, for example, strong earthquakes. Thus, as a result of the 2004 earthquake in the Indian Ocean, the length of the day decreased by approximately 2.68 microseconds. Such changes have been noted and can be measured with modern methods.

In 1967, the International Committee of Weights and Measures adopted a fixed second, without reference to the current length of the solar day on Earth. A new second became equal to 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of the ground state

Can every adult define what a day is? If you think about it, we often use this word only for the time when we are awake, equating them to the day. But this is not true. It will take very little time to sort this issue out once and for all.

What do the reference book and dictionary say about this?

If you look into them, you will find several interpretations of this word. And the first answer to the question of what a day is is the following definition: a unit of time that is equal to the approximate value of the period of revolution of the planet Earth around its axis. Why approximate? Because it is not smooth, but has minutes and even seconds. To be precise, 23 hours 56 minutes 4 seconds. It is impossible to divide them into an even number of parts. And 24 hours is just a little short.

But the theory does not stop there. It turns out that a day can be solar and sidereal, planetary and used in civil life.

In order to determine what a day is, you will need to select any point in time and count 24 hours from it. Usually the counting of the day begins with sunrise, although it is more convenient to count from midnight. That is, from the hour when a new calendar day begins.

How is the day divided?

Firstly, into 24 equal parts. From here the answer to the question logically follows: Exactly 24. Each of them consists of 60 minutes. This means there are 1440 minutes in a day. But that's not all, the latter are divided into seconds. Their number turns out to be 86,400.

Secondly, there is also such a thing as time of day. In other words, morning, afternoon, evening and night. Here the division is no longer as clear as in the previous paragraph. This is due to the subjective perception of the day by each person and different nations. And technical development has erased the boundaries between the concepts of “morning” and “day”. If earlier morning came with sunrise, because only then could one start working outside, now, with the use of artificial street lighting, one can work in the fresh air even at night.

And yet, technological progress and the ability to communicate with people from different countries required the introduction of a single division. Therefore, the time of day according to the clock became like this:

• from midnight to 6 o'clock - night;
• the next six hours are morning;
• 6 hours in the afternoon - day;
• the last six hours are evening.

What divisions of the day were there in the past?

The Arab peoples, for example, highlighted the following moments in the development of the day:

• dawn;
• Sunrise;
• the time of its movement across the sky;
• entry;
• twilight;
• the time when there is no sun in the sky, that is, night.

The next thing in the day is dawn, another name for it is dawn. It precedes the sunrise. That is, during it it is already dawn, but the sun is still hidden behind the horizon.

The third period is sunrise. It is associated with the direct appearance of the luminary in the sky.

The culmination of the sun's movement is associated with the next time of day - noon. Toward evening comes the time that is commonly called “before dark.” By analogy with the term “dark,” this is the period when it is still light.

Sunset refers to the time when the sun disappears below the horizon. Immediately after sunset, semi-darkness sets in, which is commonly called twilight.

What's bigger than a day?

It is logical that week, month and year. Therefore, after solving the question of what a day is, you will want to understand the definitions of other units of time.

The smallest of them is a week. It consists of seven days. The calendar starts from Monday and ends on Sunday. But it can be any sequence of seven consecutive days.

A slightly larger month. It contains from 28 to 31 days. The difference in this amount depends on the non-integer value of the lunar month, which is slightly more than twenty-eight days. Initially, the number of days in the months alternated and was either 30 or 31. And one, the last of the year - February - turned out to be the shortest. It had 29 days. But over time there have been small changes. One of the months - July - was named in honor of Julius Caesar (the emperor was born in this month). The ruler was replaced by Augustus. By the decision of the emperor, one of the summer months began to bear his name. The number of days in it was also changed to 31. It was decided to take it away from the month that was already the shortest. So, February became another day shorter.

The largest unit of time in the calendar was the year. And it also turned out to be not an integer. Therefore, its value ranges from 365 to 366. The first value is taken for common years, and the second corresponds to leap years. The latter make it possible for February to become somewhat longer. Namely, exactly for a day.

We master most commonly used concepts in early childhood. Despite the age of the children, it is unlikely that any of the children require an academic explanation of the simplest concepts - mother can explain everything literally on her fingers, in simple words. For example, “day is when the sun is shining” or “when you are walking and not sleeping in a crib.” Explanations quietly accumulate and systematize, forming an understanding of the term.

Meaning of the word "day"

If you look at the planet from the outside, you can see a very clear division into day and night sides. Formally, the simplest explanation turns out to be correct from the point of view of astronomy - daylight is considered to be the time when light from the star around which this planet rotates falls on the surface of the planet.

We believe that day is the daylight hours, and the weather does not play a role. Somewhere there, above the clouds, the sun is still shining, therefore, it is not night now, it is not dark around. In the circumpolar latitudes, this very principle is observed - concepts such as “polar day” and “polar night” are based precisely on natural illumination.

In some cases, this means time in general. For example, when they say “those were the days of sorrow” or “in those distant days,” we are talking about some distant time in the past when some events took place.

Dividing the day into parts

Theoretically, if we rely specifically on the presence of the sun in the sky, the day is divided into two relatively equal parts - day and night. In practice, it turns out that there is morning and evening, which are also illuminated to one degree or another. Morning begins when the reflection of the approaching sun appears in the sky, although technically it is still night. When the sun appears above the horizon, dawn begins, morning continues and lasts for several more hours until the sun rises to its zenith.

In most cases, day is the time from approximately noon to evening when the sun begins to decline above the horizon in the west. At the same time, they say “ten o’clock in the morning,” but “eleven o’clock in the afternoon,” and even in this case, variations are possible.

How many hours does a day last?

An average of six hours passes between morning and evening, and this is an approximate period. It turns out that a day is only a quarter of a day. The rest of the time is occupied at night and in intermediate states - morning and evening.

If a qualifying adjective is added, it becomes easier to determine what exactly is being said. For example, “daylight” clearly indicates that we are talking specifically about daylight hours, when the inclusion of additional sources of artificial lighting is not required. When explaining what a day is, it is advisable to immediately place emphasis and clarify that much depends on the specific situation and context, otherwise mutual misunderstanding may arise.

Often the length of the day is determined not by the actual number of hours or the duration of natural light, but solely by subjective sensations. A long or even endless day means that either a person cannot wait until evening, or he has managed to complete many different tasks.

Specification of time intervals

The word “day” is often used to mean “day”. For example, “you have three days to eliminate the shortcomings.” In the meaning of “day”, this word is used when you need to indicate a sufficiently long amount of time.

If you need to set some limits, then it can be a “working day” - the interpretation in this case provides that weekends and holidays are not considered. Working days take into account business obligations - fulfillment of orders, receipt of funds in a bank account, and so on. The outdated concept of “workdays” has a similar meaning; this is a unit for recording the labor of collective farmers for subsequent payment. When they say “day off,” they mean a day free from all kinds of work duties, a time intended for rest.

When trying to understand what a day is in the minds of another person, we usually try to simplify mutual communication as much as possible. Therefore, when they tell us “call tomorrow afternoon,” it is better to clarify in what time period the call will be appropriate. For some, eight o’clock in the morning is already day, while others are still sleeping. If you don’t specify, then according to business etiquette, a day is considered on average from 11 a.m. to 4 p.m., and it would be good practice to fit in approximately in the middle of this interval. In other cases, it is better to ask for the exact time.

“We’ll see you tomorrow morning”, “we’ll call you in the morning”... We use such phrases quite often, only then it often turns out that everyone’s morning begins and ends at different times. How much time can really be considered morning?

In fact, it’s hard to say for sure when the morning begins. There are a lot of definitions - folk, astronomical, official - and each of them in its own way defines the boundaries between times of day. Some people generally use a simple principle “When I woke up, then it was morning”, so it turns out that for some, morning is five o’clock in the evening.

Until man began to use artificial lighting, morning began with sunrise, and evening began with sunset. The length of daylight hours determined the length of the “working” day. Some people still use this distinction, but the times of dawn and sunset shift depending on the time of year - the division of the time of day is too unclear. In addition, it is not clear how to draw the line between evening and night, morning and day. That is, it is clear when the morning begins, but it is impossible to objectively determine when it ends and the day begins.

In addition, each language has its own stable expressions related to the time of day. For example, in Russian they say “two o’clock in the morning,” but in most cases they say “four o’clock in the morning,” that is, four o’clock is already morning, although in winter it may still be dark outside the window at this time. But, unfortunately, such descriptive constructions do not help to clearly distinguish between morning and day, evening and night: it happens that someone is used to saying “three o’clock in the morning,” and someone is used to saying “three o’clock in the morning.”

And in many English-speaking (and not only) countries it is generally customary to use 12 hour clock, and divide the day into only two periods - before noon (a.m., ante meridiem) and after noon (p.m., post meridiem). It is not customary for them to use descriptive constructions (although this does not mean that they do not use them at all), so the problem of dividing the time of day remains.

So it turns out that every country, and even every person has his own subjective perception of time of day, associated with the customs of the country and one’s own daily routine. For example, most office workers associate morning with the beginning of the working day, afternoon with the lunch break, and evening with the end of the working day.

But still, is it possible to somehow bring this into unified system, and distinguish between the times of day in order to clearly understand when the morning begins and ends? This way a lot of misunderstandings could be avoided!

Most European countries have adopted a single division of the day. According to this division, the day is divided into four equal intervals of six hours each. It turns out that the times of day are distributed as follows:

• from 0 to 6 o'clock - night
• from 6 to 12 o'clock - morning
• from 12 to 18 o'clock - day
• from 18 to 24 hours - evening

It is reasonable to use such a system, for example, in business communication, when you need to be 100% sure that the morning of the customer and the contractor coincides: it happens that the contractor is sure that he sent the work to the customer in the morning, as agreed, and the customer It's already day. And how will you understand who is right and who is wrong if everyone judges by their own criteria? This is why we need a pan-European system - so as not to wonder “When does the morning end and the day begin?”