The effect of daylight saving time on student sleep quality and mood

The transition to permanent daylight saving time in Turkey aims to benefit from more daylight and save electricity. However, this practice may lead to a later sunrise in the winter months, resulting in a decrease in the amount of daylight exposure. In addition, it is known that natural light has effects on individuals on the sleep-wake cycle, mood and general health. However, studies examining its effect on adolescents are scarce. Therefore, it aims to investigate the effect of permanent summer time on sleep quality and mood on students. For this purpose, a study was conducted on 9th and 10th grade students in Bursa Bahçeşehir College in six different branches. During the research process, the indoor illuminance levels of the classrooms where the students were educated were measured for four days. In addition, various scales were used to determine students' sleep quality, sleepiness, depression, anxiety and stress levels. According to the results obtained, it was determined that the sleep quality of the students was low, they experienced sleepiness during the day, and they had depression, anxiety and stress levels. Considering the decrease in the amount of daylight in the permanent daylight saving time, it can be said that there is a negative effect on students. However, no significant relationship was found between the indoor light levels of the classrooms in which the students were educated and sleep quality, sleepiness, depression, anxiety and stress. This shows that the effect of indoor lighting levels that students are exposed to in classrooms is not sufficient. As a result, it has been observed that the natural light levels that students are exposed to in their daily lives have negative effects on sleep quality, sleepiness, depression, anxiety and stress. However, it was determined that indoor lighting levels in the classrooms did not have a significant effect on these effects. These findings support that exposure to high levels of natural light outdoors has a significant effect on sleep quality and mood.