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 1861, the Astronomical Observatory of Lisbon was founded and, in 1878, it was tasked with the exclusive competence of calculate its mean solar time and to transmit it to rest of the country’s public services. Thus, in practice, Portuguese standard time was defined as the mean solar time at Lisbon Observatory longitude, which was later calculated as being GMT–00:36:44. In 1911, it was agreed that standard time in Portugal should be defined in accordance with the 1884 prime meridian system. By the Decree of 26 May 1911, a reform was approved regarding standard time in Portugal and in its overseas