Catalan children under 15 years of age sleep less than their Galician counterparts, which could be due to the fact that they share similar schedules but live at opposing longitudes of the country, according to a study led by Juan Carlos Martín and Àurea Cartanyà-Hueso, researchers from the Evaluation Group on Determining Factors in Health and Healthcare Policies.

In Spain, the day starts one hour later on the west coast compared to the east, and yet the whole country runs on the same time zone. This could have consequences on how much children under the age of 15 in Catalonia are sleeping, as “they should go to sleep an hour earlier, but bedtimes are the same across the country”, explain the researchers.

The report "Differences in sleep duration in a territory with the same time zone according to the geographic longitude: the Spanish case", which surveyed 1,000 children from Catalonia and Galicia and was published in the journal Sleep Medicine, found that the duration of sleep is often insufficient in Catalonia, which could be due to its longitudinal positioning.

Given these results, researchers are advocating timetables be governed by the position of the sun, since “while standardising a country’s timetables may have some advantages, they do not outweigh the drawbacks”.

Similar studies have so far not been carried out elsewhere as “there are few countries in the world with sufficient distance between their eastern and western borders to require more than one time zone, but which use the same time zone for the whole territory,” say Juan Carlos Martín and Àurea Cartanyà-Hueso, the study’s leading authors.