A seasonal rain front hovering over Northern Kyushu from July 6 to 8, 2020, and warm, moist air flowing from the outskirts of the Pacific anticyclone caused record-breaking heavy rains in a wide area. From 0:00 on July 7 to 24:00 on July 8, the Automated Meteorological Data Acquisition System in Omuta recorded 388.5 mm of rain—the most daily precipitation and 48 h of precipitation exceeding 600 mm in several areas, including Minamichikugo District in Fukuoka Prefecture and Yamaga and Kikuchi Districts in Kumamoto Prefecture, that expanded linearly east–west 40 km and south–north 20 km across southern Hita in Oita Prefecture. The heavy rain caused inland waters in Omuta to flood, two people died, and the number of damaged houses totaled 2,054, with 11 completely destroyed, 1,341 inundated above the ground floor, and 713 inundated under the ground floor. In particular, in the Mikawa District on the left bank of the downstream Suwa River, torrential rain overflowed the Mikawa pump station’s drainage capacity of 64.4 mm/h, and when the drainage function collapsed, the station flooded, as did 800 houses—up to nearly 2 m in the Mikawa District—many of which have yet to be restored. Severe flood damage occurred in Shioyamachi, Higuchimachi, and Kamiyashikimachi 1 chome and 2 chome in the Mikawa District. Those areas, once low flatlands of lotus root fields and rice paddies before World War II, experienced rapidly progressing division maintenance in the 1960s following reclamation. Such development at a low altitude with a high risk of flooding further expanded the damage.

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Previous research on time use on sociology of education or sociology of children has shown class inequality and regional inequality in children's daily life or time-series changes in specific actions. However, much less is known about comprehensive trends in children's lifestyles in Japan. This paper examines trends in children's lifestyles between 1970 and 2020, by analyzing data from NHK’s Japanese Time Use Survey Data. We use data on elementary school students over 10 years, junior high school students, high school students, and 40s as their parents' generation, and confirm time-series changes in time use from information on the amount of time (how much time they do) and timing (what time they do). The results show that with regard to time-series trends in time use in the nighttime, tendency for elementary school students is similar to that for 40s, while tendencies for middle and high school students are independent of that for 40s. The diversity of daytime in weekdays has been stable for 50 years, but the diversity of daytime on Sundays has no consistent trend of change or stability. The diversity of nighttime in weekdays and Sundays for every group has expanded, but while 40s and elementary school students have gradually become night owl, middle and high school students have been night owl and have increased their free time. Our findings indicate that analysis using information for both timing and the amount of time is effective in examining lifestyles from time use data, and that time use study is important for investigating children's socialization in a long-term and objective perspective.

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The purpose of this study was to examine whether children's time management affects their study time during the long vacation and their motivation to study after the long vacation. We measured children's time management--establishment of life rhythm, setting goals and priorities--and study plans before the long vacation, daily study time during the vacation, and self-efficacy and motivation to study after the vacation. As a result of analysis, it was found that children who scored higher in the establishment of life rhythm were more consistent in their homework plans and actual efforts, and spent more time studying. In addition, the establishment of life rhythm had a positive effect on motivation to study and self-efficacy, and setting goals and priorities had a positive effect on self-efficacy.

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This paper considers what the ideal time theory was from the perspective of breathing in China. The theory that a person breathes 13,500 times a day is described in the Ling shu, the oldest surviving medical texts in China, and later became a theory that supporting Zhu Xi’s idea of space operation. The word xi, which means nasal breathing, has already been associated with short time since the Western Han era, functioning as a unit of time to a certain extent. The 13,500 breathing theory has been introduced into Japan and is presented in numerous commentaries to the Nihon shoki, but there is also a new theory development can be seen, which is the Japanese breathe less each day than the Chinese. And Ichijo Kaneyoshi states in his Nihon shoki sanso that this theory can be used to tell time. In fact, it seems that Sun Wukong, the main characters in the Journey to the West xiyouji, have practiced that theory. On the other hand, after the Southern Song Dynasty, a new theory of knowing time by taking turns breathing through the nostrils, and it is described in Yu Yan’s Fu shang xi tan and Fang Yizhi’s Wu li xiao shi Moreover, a further development of this theory can be found during the Republic of China, however, the traditional Chinese theory of breathing and the ideal time for breathing were eventually destroyed been disrupted by the advent of Western scientific knowledge and modern medicine during this period.

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Many ancient documents refer to events held yearly. In China, these include the Shijing （seventh month）, the Liji （monthly proceedings）, the Dadai Liji （almanac）, the Simin Yueling and Yi Zhou Shu （time and monthly proceedings）, the Jingchu Suishiji and Guanzi （holidays）, the Lüshi Chunqiu （twelve parts of the year）, the Huainanzi （seasonal regulations）, and the Sancai Tuhui （time proceedings）. In Japan, these include the Honcho Gatsuryo, Ryocho Jirei, Nihon Saijiki, Toto Saijiki, and Kujo Nenchu Gyoji. By reading these documents, we can learn what took place at what times during the year, but we have no way of knowing what took place at what time of day. However, the mid early modern text of the shomei inscription at the former Kurobane Castle （in Shimotsuke Province, now Tochigi Prefecture） indicates the daytime activities of the common people hour by hour. Furthermore, the Sosui Kakei political historical materials of the former Kurobane clan, established in the late early modern period, include records of the actions that were to be taken by the domain lords at specific hours. This study addresses the records of the common people’s daytime activities by the hour within the shomei inscription at the former Kurobane Castle, referring to the Sosui Kakei and alternate names for the Asian zodiac in order to decipher the records using specialized sinological （Chinese studies） methods. This process has resulted in the clarification of the common people’s daytime activities in the former Kurobane domain hour by hour in the mid–late early modern period.

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We experience two kinds of time, namely, physical time t and psychological timeτ, simultaneously. In this paper, loci of the variables (t,τ) through a life time were analyzed ,especially at the beginning and the final stages. The relativistic effect on times was ignored because of the low speed. A nondimensional parameterαwas proposed, which represents the vital body functions. α is a function of physical time t. It was supposed thatαtakes the value of zero at the beginning time and the ending time of life, while in intermediate normal time it takes a value of nonzero positive value of order 1. The functionαwas supposed to be continuous and differentiable. On the other hand, a human being has a mind, which creates psychological timeτ. Each of three variables t,τand α does not change independently. The differential equation (1) which combines the three variables was proposed as follows (Equation of Two Times or shortly Life Index Equation). dt/dτ=α(t) (1). The function form of α(t) was proposed by applying Taylor's theorem without losing generality. Under the above conditions , (t-τ）locus was calculated. The results are as follows. Suppose a lifetime of a person, [t_1,t_2],on t-τplane. The locus is described in the form of τ(t)=f(t),in which t_1≤t≤t_2 . (1) f(t) is a monotone increasing function. (2)While physical time t moves in a finite interval (t_1,t_2) , psychological timeτchanges in an infinite region (-∞,+∞). In other words, lifetime is finite objectively, nevertheless it is infinite subjectively.

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We live by using the time for learning and working, a leisure, a rest. Therefore the time is a key concept of our utility. If I make a model of utility constructed by these time, then I consider what this model explain. First of all, I suppose that our utility organizes by a wage and a leisure time. In this time, I suppose that the wage which construct this utility arise by human capital and working time. And also suppose that this human capital arise from leisure time and working time. From this view, we result that both working time and leisure time influence to our utility. That is, I can construct the model by these time. We have a balance of the effect for this utility from both working time and leisure time. Then working time enhances our human capital or our working productivity. This means to equal that leisure time enhances our human capital or our utility.

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