MULTIPLE-SHIFT SCHOOLING: INTERNATIONAL CONTEXT AND THE BRAZILIAN CASE TURNOS ESCOLARES: CONTEXTO INTERNACIONAL E O CASO BRASILEIRO TURNOS ESCOLARES: CONTEXTO INTERNACIONAL Y EL CASO BRASILEÑO

The article systematizes the main concepts, arguments and characteristics of multipleshift schooling in the international context and in Brazil, through bibliographic and documental research. The presentation of the specificities of the multiple-shift schooling in different countries provided elements for the analysis of the Brazilian case. The article highlights the emergence of multiple-shift schooling in the early twentieth century, its widespread nationwide, the emergence of experiences of extended school day, the naturalization of the multiple-shift schooling in the country, the diversity of shifts, school day and schedules and the recent goal of full-time education. Expanding the provision of full-time education does not necessarily mean eliminating multiple-shift schooling. There are still numerous challenges for public schools (half-day or fullday). Analysis of school day and full-time education associated with multiple-shift schooling may bring new perspectives to the formulation and implementation of educational policies.


INTRODUCION
Historically, advocating for universal education has required education systems to expand, demanding more places, schools and teachers. "Education for All" movement led by the United Nations Educational, Scientific and Cultural Organization, exemplifies the effort many countries have been taking in recent decades to achieve this goal (UNESCO, 2015). However, in several countries, the relation between supply and demand has not always been appropriate. In the search for alternatives to democratize and universalize education, the creation of school shifts aimed at the use of the same school space by different groups of pupils. However, in many education systems, the constraints on physical space and school have impacted on education quality. Furthermore, in various contexts, what should be a palliative and provisional measure, has been prolonged and even expanded.
Investigations about school shifts have a direct interface with the thematic of the school day, as they are related to the organization of the pupil's time at school, the instruction time and the type of compulsory schooling offer. Currently, according to the studies presented in this article, several investigators have been focusing on the theme school day, favoring analyzes on its expansion and, in some cases, identifying changes in the configuration of the school and in the school shifts, where these have been implemented. This is because, as a rule, extending the school day means implementing policies to eliminate school shifts, partially or totally.
International reports show that, on average, countries offer between 4 and 6 hours of school day (OECD, 2018). However, depending on each country, the school may operate in one, two or three shifts to meet demand.
The analysis of the school day in different countries shows that school shifts are associated with problems in the education systems structure, usually occurring in developing countries, which fail to offer adequate educational infrastructure, especially in terms of financial, physical, material and human resources.
In many contexts, as they have been in existence for a long time, school shifts are practically part of the education system structure, which makes it difficult to conceive the functioning of the school without them. In these countries, school shifts are accepted as commonplace and therefore many people think that this model of offering formal schooling at different periods (morning, afternoon, night) to various groups of pupils occurs in all education systems.
Although school shifts still play an important role in ensuring universalization and democratization of education in many countries -some of which have had the option of investing in infrastructure and have not done so -the fact is that their maintenance, to a large extent, restrict the extended school day policies, the provision of extracurricular activities and teaching work, aspects that act as variables (although not limited to them) in the quality of school education and the integral formation of children, adolescents and young people in compulsory school age. Precisely for this reason, in several countries, formulating extended school day policies means eliminating school shifts, the first challenge for implementing an extended school day or full-time school.
In the literature of the area, some investigations on school shifts aim to analyze possible differences in the performance of pupils who study in different shifts (morning and afternoon, for example) or in diverse shift systems (single shifts and double shifts). These studies reveal that, in addition to other variables, school shifts can also act as an aspect that enhances external and internal inequalities in the education system. Given this scenario, through bibliographic and documentary research, the objective of this article is to systematize the main concepts, arguments and characteristics of school shifts in the international context and in Brazil. Based on this investigative effort on school shifts internationally, this study aims to contribute to the analysis and systematization of the Brazilian case. In addition, it proposes narrowing the discussion between school shifts, school day and fulltime education, offering new elements to the political decision-making process.

SCHOOL SHIFTS: NECESSARY EVIL?
Single-shift schools (single-session schools, unisessional schools or full-day schools) serve only a group of pupils during the day, regardless of the number of daily hours the pupil spends at school. Given the definition of a single-shift school, it is then possible to conceptualize double-shift schools (double-session schools, bisessional schools and half-day schools). In the Spanish language, double-shift schools are named escuelas de doble turno. Generally, double-shift schools present [...] two entirely separate groups of pupils [...]. The first group of pupils usually attends school from early morning until mid-day, and the second group usually attends from mid-day to late afternoon. Each group uses the same buildings, equipment and other facilities. (BRAY, 2000, p. 10).
In addition to double-shift schools, there are also schools with multiple shifts 2 , with three (triple-shift school) and four shifts (quadriple-shift schools).
In the 1980s, after presenting the considerations about the reality of sub-Saharan African countries 3 and discussing school enrollment rate in some countries, a study by the World Bank found that the average number of pupils per class often exceeded 50 students. According to the study, overcrowded classrooms are unfavorable for learning and, therefore, recommended, among other measures, the reduction of the number of pupils per class through the implementation of double shifts (WORLD BANK, 1988).
Studies on school shifts show that their main objective is to increase places without major impacts on the budget, using the same school building to serve more pupils. This political decision helped many countries to move towards universalization of education. BRAY (2000) 4 , in one of the studies most referenced by those investigating the theme, lists the main arguments for implementing school shifts: expanding the offer of places, seeking universalization of education and social equity; maximizing available human resources, allowing the same teacher to work in two shifts; doubling the working hours of education professionals, improving pay; enabling poor children to study in one shift and work in the other one to help their families; reducing the number of pupils per class. Despite some pointed benefits, contradictions are evident, that is, unresolved social and educational problems, such as teacher devaluation, low remuneration of professionals in education and child labor. Linden (2001), in a study carried out for the World Bank, analyzes school shifts in secondary schools in different countries, focusing only on double-shift schools. Among the reasons for implementing school shifts, the author mentions: increasing the efficiency of human and physical resources, using existing teachers and spaces; expanding the number of places; improving teacher's salary without increasing costs; making it possible for pupils to work in the opposite shift to school; reducing school overcrowding.
In another investigation carried out for the World Bank, Larach (2001), when referring to Brazilian high schools, highlights the fact that many pupils, because they work full-time during the day, attend school at night, showing that, in addition to daytime shifts, Brazil, among others, has night schooling. Orkodashvili (2009), in a literature review, concluded that the main advantage of school shifts is to contribute to achieving the goal of offering universal education for all, both in poor and rich countries. Figure 1 shows how the implementation of shifts enables greater rationalization of school buildings. In the single-shift system, 6 schools serve the same number of pupils as 3 double-shift schools or 2 triple-shift schools. Precisely for this reason, schools with shifts are generally found in poor or developing countries, although double shifts are also found in rich countries such as in Singapore (BRAY, 2000).  Source: Bray, 2000, p. 13 Despite the mentioned benefits, especially associated with democratization and universalization of education, in a school with shifts "[...] quality is being sacrificed for quantity" (BRAY, 2000, p. 12), that is, the school day and the offer of extracurricular activities are constrained. Therefore, among the negative aspects of school shifts are the costs associated with care in the opposite period to school and extracurricular activities, as well as social costs. While the child is at school, parents work and develop other activities. If the child is not at school or attends a few hours, care strategies must be provided, which may occur in different ways: by the parents themselves (who do not work or need to reduce their working hours), by family members, by paying professionals to take care of the children, by hiring private services or receiving support from public or private socio-educational institutions. In addition, in the case of the absence of care strategies, there may be an increase in social vulnerability. According to Bray (2000, p. 37), "although the government may save money through a double-shift system, it may have to spend money to deal with social problems" or by paying for social and educational public services.
The shift system can also be typified in relation to other aspects: as for school time, as for the teacher and as for the schooling level. As for school time, the so-called end-on shifts is a model in which the first group of pupils (in the morning) leaves before the arrival of the second group (in the afternoon). However, some models allow common moments in which morning and afternoon classes overlap. As for professionals, one same teacher may work in two shifts or different teachers may work in each shift. In some countries, school shifts are organized according to the schooling level, that is, some schooling levels or grades work in the morning shift and others in the afternoon shift. The shifts may be also alternated, that is, certain groups attend classes in the morning shift and, after a while, they go to the afternoon shift (BRAY, 2000).
Researchers studying school shifts, in addition to highlighting the arguments for their implementation, tend to point out the movements that many countries have been making towards their elimination. Ashong-Katai (2013), when summarizing some studies, highlights that the main reason for eliminating school shifts is to improve the quality of education. According to the author, countries such as Jamaica, Maldives, Oman and Turkey have defined the abolition of school shifts as the goal of the education system.

SCHOOL SHIFTS IN THE INTERNATIONAL CONTEXT: SOME ILLUSTRATIONS
In the European continent, in general, compulsory schooling occurs through single shifts, covering two periods (morning and afternoon) or with concentration of the instruction time in the morning. The pupil's time at school can be extended through supervised or extracurricular activities named extended school day activities 5 . However, some countries offer double-shift compulsory schooling, such as Bulgaria and Croatia. In Bulgaria, single-shift and double-shift schools (half-day and whole-day) coexist. Croatia has double-shift schooling for secondary education, that is, a morning shift and an afternoon shift, each with a different group of pupils. In primary education, classes take place only in the morning, but extracurricular activities are offered in the afternoon. In Portugal, compulsory schooling in basic education takes place in a single shift (morning and afternoon), with a break for lunch. However, the legislation allows double shifts in case of place problems, which happened decades ago (EUROPEAN COMMISSION, 2020).
In the African continent, double shifts are present in many countries, such as Burkina Faso, Gambia, Ghana, Namibia, Nigeria, Senegal, Tanzania and Zambia. In Senegal, shifts were implemented in 1982, where the same teacher may work two shifts, with a 25% additional on the salary. There is a difference between the weekly instruction time in single-shift schools and double-shift ones (28 and 20 hours, respectively), with an increase in school days to compensate. 5 Extended school day policies refer to different political-pedagogical strategies that extend the pupil's time at school, which can occur by increasing the hours devoted to the school curriculum, offering extracurricular activities, supervised care time or school meals. Generally, when the policy covers all of these activities and the pupil is under the responsibility of the school during that period, this policy is called educação em tempo integral (Brazil) and escuela a tiempo completo (Latin-Hispanic countries). Research or information on these policies, when published and translated into English, may have different names: the term full-time school has been used by Latin American researchers; the term all-day school has been used by researchers from countries as Germany, Austria and Cyprus; the term whole-day was found as a translation of existing policies in Bulgaria and Hong Kong.
In Nigeria, teachers cannot work in two shifts, as this is believed to bring consequences for the quality of education. Studies in the country have shown differences between pupils attending single-shift schools and double-shift schools, revealing negative aspects of the shift system (BRAY, 2000;USMAN, 2015).
In Zambia, there are daytime triple-shift schools, which directly cause a reduced instruction time: 1st shift (7 am to 10:45 am), 2nd shift (11 am to 2:45 pm) and 3rd shift (3 pm to 6:45 pm) (USMAN, 2015). In Namibia, the double-shift system was implemented in 1975 (HARPER, 1987apud USMAN, 2015. In Tanzania, even with investments in building schools, the increase in enrollments led to the need to implement school shifts (UNESCO, 2009).
In Ghana, shifts have been around since the 1960s. They were created as a temporary measure, until classrooms and schools were built to supply demand. Nevertheless, the country has been trying to formulate and implement policies for its elimination. The same teacher is not allowed to work in two shifts. Instruction times in single-shift schools differ from double-shift schools (22 hours and 55 minutes and 19 hours and 35 minutes, respectively), which shows discrepancies between the two systems. For this reason, groups of pupils alternate shifts: some groups attend classes in the morning and others in the afternoon; after a while, these groups alternate their shift (BRAY, 2000;ASHONG-KATAI, 2013).
In the Asian continent, the literature indicates that many countries have resorted to the shift system, including: Bangladesh, Cambodia, Singapore, South Korea, Philippines, Hong Kong, India, Indonesia, Malaysia, Myamar, Palestine and Vietnam. In Bangladesh, pupils enrolled in the early grades study in the morning; pupils enrolled in later grades study in the afternoon. In Singapore and South Korea, the teacher cannot work in two shifts. In Palestine and India, pupils are divided based on their level, primary and secondary education, for example (BRAY, 2000). In Mexico started implementing school shifts from the 1950s. Several studies on the country report differences between pupils attending morning shifts and afternoon shifts: pupils in the afternoon shifts have higher failure rates, higher ages and lower performance. The afternoon schools are known in the country as "low quality" and "for the poor" schools (CÁRDENAS DENHAM, 2011). Research indicates that teachers working more hours daily have negative effects on pupil performances in both shifts, morning or afternoon (SAGYNDYKOVA, 2015) and, therefore, extending the school day, eliminating shifts and implementing complete workday for teachers are elements that have an impact on the pupils' learning (GARCIA, 2004). Nevertheless, it is important to be cautious to avoid that extended school day policies generate more inequalities (CÁRDENAS DENHAM, 2011). In addition to morning and afternoon shifts, Mexico also offers schooling at night, usually for adults (ARCEO-GOMEZ; CAMPOS-VÁZQUEZ; MUÑOZ-PEDROZA, 2016).
In the literature, Chile is referred to as an example of a country that undertook a largescale reform to eliminate school shifts. In 1997, the country started to implement the so-called Jornada Escolar Completa (full-time school), a year in which only 20% of pupils attended the fullday shift schools; in 2014, data showed that this type of offer was almost universal (HOLLAND; ALFARO; EVANS, 2015; DOMINGUES; RUFFINI, 2018).
Additionally, Sagyndykova (2015) mentions that double shifts are adopted on an emergency basis in cases of natural disasters, as has already occurred in Florida, in the United States. The bibliographic research also found studies from the 1950s that mentioned comparative investigation between half-day schools with double sessions and full-day (regular-day programs) in the United States (HENDRICK, 1954), that is, a few decades ago, in the North American country, the two systems coexisted.
In Brazil, studies on school shifts are scarce. The focus of the investigations is on policies that extend the school day, that is, the so-called full-time education, without a deeper analysis of its background, which would lead to the history of the creation of school shifts.
In the Brazilian context, school shifts emerged at the beginning of the 20th century. At the end of the 19th century, the country witnessed the phenomenon of the constitution of education systems in Europe and the United States. In many countries, the universalization of education was already in consolidating process. During this period, São Paulo state started organizing graded schools, that is, schools with a vertical system for successive courses.
The main characteristics of graded schools are: a) grouping of pupils according to a leveling criterion, which, in general, is the chronological age to obtain homogeneous groups; b) teachers assigned to each grade; c) equivalence between a pupil's school year and a year of instructional progress; d) prior determination of the contents of the different subjects for each grade; e) pupil's performance is determined according to the level established for the group and the level at which they are found; f) rigid and inflexible promotion of pupils grade by grade. (DICCIONARIO DE LAS CIENCIAS DE LA EDUCACIÓN, 1983apud SOUZA, 1998.
Inspired by the trajectories of countries as Spain, France, England and the United States, São Paulo state started to invest in the expansion of graded schools and, consequently, in the increase of their places.
In Brazil, graded schools of primary education, comprising multiple classrooms, several groups of pupils and several teachers, appears for the first time in public education, in São Paulo state, in the 1890s. [...] In this state, public education reformers were able to see graded schools -schools of a new type -as an improvement and as a factor in education and cultural modernization. (SOUZA, 1998, p. 38-39).
With the 1892 Reform, schools in São Paulo operated with full-day shifts, that is, morning and afternoon, for 5 hours, from 10 am to 3 pm in winter, and from 9 am to 2 pm in summer. In 1904, the schedule changed from 11 am to 4 pm (SOUZA, 1999). In the European context, the Spanish school of the early 20th century operated in a similar way: morning and afternoon, 3 hours each period, totaling 6 hours daily (ESCOLANO BENITO, 2000). Even today, this format prevails in many European countries, although some choose to concentrate classes in the morning.
Also in São Paulo state, in 1908, school shifts emerged as a way to double places. Schools started to operate in two shifts for different classes: morning (8 am to 12 pm) and afternoon (12:30 pm to 4:30 pm). Nevertheless, the full-day shift was still adopted in some schools (SOUZA, 1998;1999).
In 1910, of the 24 schools in the city of São Paulo, 17 operated in two periods. In the countryside, of the 77 schools, 20 operated in two periods. Unfortunately, what was supposed to be provisional has become the rule. (SOUZA, 1998, p. 102).
Faria Filho and Vidal (2000) show that school shifts were also implemented in the same period in Minas Gerais state due to the low attendance capacity. However, the new system did not occur without resistance: principals at the time claimed that shifts produced disadvantages in terms of hygiene and discipline, in addition to difficulties in adapting pupils and parents to the new hours of starting and leaving school. Both Souza (1999) and Faria Filho and Vidal (2000) reported that the morning shift affected the lunch habits, which, at the beginning of the 20th century, took place between 9 am and 10 am.
In addition to double shifts, in 1928, "triple division" (triple shifts) were created, from which school activities lasted three hours in each shift. In 1955, some schools started to have four shifts to meet the school demand (SOUZA, 1998).
Throughout the 20th century, school shifts were widespread across the country. During that period, some states and municipalities implemented actions and policies with the objective of offering more time for the pupil at school (full-time school), which would enable a formation that covered different aspects of the human being (integral education). This is the origin of the term "integral and full-time education". Two recurrent examples are highlighted in the literature of the area: in the 1950s, the construction of the Educational Center Carneiro Ribeiro, in Salvador, in Bahia state, idealized by Anísio Teixeira, where pupils stayed in a Escola-Classe for 4 hours and 4 more hours at Escola-Parque (ÉBOLI, 1969); in the 1980s, the creation of the Centros Integrados de Educação Pública (CIEP) in Rio de Janeiro state, where the pupil had a nine-hour day (MIGNOT, 1989). These and other experiences were never unanimous: firstly, because they were residual, which promoted inequalities within the educational system; secondly, because they brought into the school the resolution of problems that were outside of it. Such dilemmas, associated with others, still persist in political decision making today.
In the Brazilian context, school shifts are so commonplace that, rarely, political discourses, academia and the population mention them. In the defense of integral and full-time education, little or no association is made regarding the elimination of school shifts. In Brazilian national educational legislation, there is no direct mention of its abolition. In the last decades, goals have been set for the expansion of full-time education, which, consequently, would mean the partial elimination of schools operating with school shifts. However, some ongoing full-time educational policies propose the extension of the school day without necessarily changing the organization of school shifts, that is, through the provision of extracurricular activities outside the school space and/or through intersectoral and public-private relationships (PARENTE, 2016).
In 1996, the National Education Guidelines and Framework Law established the progressive expansion of the full-time education in the elementary education 6 . Currently, the country defines two types of school day in the basic education: half-day school with at least 4 hours and full-time school with at least 7 hours (BRASIL, 1996;. The National Education Plan, approved in 2001, indicated that full-time school -associated with the provision of sporting and artistic activities, study guidance and also with the expansion of the provision of school meals -should favor younger children, from disadvantaged social strata and whose parents worked. The plan's goals foresaw a progressive expansion of full-time in early childhood education and elementary education (BRASIL, 2001). Unfortunately, the implemented policies were not sufficient to meet the established goals.
In 2014, the new National Education Plan set a goal of offering full-time education to at least 25% of basic education pupils and at least 50% of public schools (BRASIL, 2014a). This goal shows the country does not aim the elimination of school shifts on a large scale as a guideline, which would require considerable investments in physical, material and human resources, in addition to a strong political engagement to do so.
Recent statistical data reveal that 82.6% of pupils receive half-day schooling and 17.4% fulltime schooling. There are 71.4% schools offering half-day schooling and 28.6% offering full-time schooling. However, many schools with full-time schooling do not apply it in their entirety (BRASIL, 2018).
Relating school shifts, school day and schedules, Brazilian school shifts may be classified into five different school shift systems: single half-day shift, single full-time shift, double shift, triple shift and, exceptionally, quadruple shift (Chart 1). In this classification, the school instruction times were generalized, considering a minimum of 4 hours a day for the half-day school and 7 hours for the full-time school. Nevertheless, there can be many variations, due to the country's 5570 municipalities in its 26 states, in addition to the Federal District, and the fact that Brazilian legislation offers autonomy to education systems for this type of definition.  As reported by Linden (2001), maintaining school shifts and/or investing in single shifts (half-day or full-day) are important dilemmas that policymakers in developing countries, such as Brazil, currently face. The author clarifies that double shifts do not need to be completely discarded. Based on this, it is possible to think about short, medium and long-term policies that focus on the problem of shifts associated with the definition of the type of school day.
When summarizing research results on the effect of school shifts on pupils' academic performance, Domingues and Ruffini (2018) indicate that the results are diverse, and it is not possible to peremptorily affirm that there is a direct relation between increased school time and good academic performance. However, such studies list some social benefits of extending school time: care time during family working hours and decreased risks related to adolescence (drug exposure, crime and pregnancy). According to the authors, the Chilean reform, which invested in the Jornada Escolar Completa and eliminated school shifts, lasted for 14 years. The Chilean case evidences that, in addition to the Brazilian goal of full-time education, concrete strategies are needed to improve the quality of education, including reviewing shifts, which means thinking about a school that has physical, material and human conditions to offer a basic and quality curriculum for all and, progressively, extracurricular activities that contribute to integral formation of pupils. An analysis of how necessary school shifts are and where they can be gradually eliminated is necessary in each Brazilian state and municipality.

FINAL CONSIDERATIONS
There are flagrant contradictions in the international scenario. In some countries, universalization of education has long ceased to be a problem; in others, it has been the greatest challenge. This reality shows that the school shift system, even with its limitations, has been an option to achieve the worldwide goal of Education for All.
The literature review offered conditions to understand the theme from different perspectives, synthesizing concepts, arguments and characteristics of shifts in different countries.
With this, it provided essential elements to support the analysis of the Brazilian case, summarize its history and trajectory, in addition to systematizing the specifics of school shifts in Brazilian schools.
In Brazil, school shifts, implemented as an extraordinary measure at the beginning of the 20th century, are now widespread and have taken the full-time school to a condition of exceptionality. The country, by having the expansion of full-time education to a portion of pupils as a goal, maintains a dual system (half-day and full-day-shift), both hampered by material still insufficient (or nonexistent) conditions in many public schools, which reflected in the variables affecting the quality of education.
Education and social arguments for implementing full-time education have been disseminated in the country. Brazilian reality shows that these arguments are inseparable: in theory, more time in school means more time in safety, in activities, in formation, with care and food. However, the insufficient investments in the construction of new schools in the last decades associated with the use of non-school spaces and the dissemination of intersectoral and publicprivate relationships are outlining the current political-educational strategies for offering curricular and extracurricular activities that make up the full-time school. This explains why it is not possible to directly associate extended school day with the elimination of school shifts.
There are several dilemmas and challenges regarding the management, organization and quality of Brazilian education. Specifically concerning full-time educational policies, they are known to benefit many pupils in compulsory schooling and are compatible with international trends in extending pupil's time at school. The analysis of school shifts associated with school day strengthened the notion that any political decision in relation to the theme must be based on solid arguments and concrete diagnoses, and that educational planning must overcome goals and strategies that are repeatedly not complied with.