Indian Ocean trade Madagascar at this time leaving behind a lasting cultural and genetic legacy. Chinese fleets under Zheng He criscrossed the Indian Ocean during the early part of the 15th century. The missions were diplomatic rather than commercial, but many exchanges of gift and produces were made. The Portuguese under Vasco da Gama discovered a naval route to the Indian Ocean through the southern tip of Africa in 1497–98. Initially, the Portuguese were mainly active in Calicut, but the northern region of Gujarat was even more important for trade, and an essential intermediary in east-west trade. Venetian interests were directly threatened as
Time in Portugal to work under a completely dark sky and at 9:00, when school classes started, the sun was still rising, which eventually had repercussions on students’ school performance and their safety during morning trips from home to school.<ref name="Decree-Law 309/76"> Decree-Law 309/76, 27 April 1976 (in Portuguese). Retrieved 12 May 2013.</ref> Furthermore, in the 1970s, the idea of reintroducing DST as an energy saving measure gained strength in Europe as well as in Portugal. However, although there were so many complaints in the country with the use of year round, it became clear to policymakers that if DST was to be