Portuguese Empire years for the Portuguese to follow up on Dias's voyage to the Cape of Good Hope, though it has also been speculated that other voyages were in fact taking place in secret during this time. Whether or not this was the case, the long-standing Portuguese goal of finding a sea route to Asia was finally achieved in a ground-breaking voyage commanded by Vasco da Gama. The squadron of Vasco da Gama left Portugal in 1497, rounded the Cape and continued along the coast of East Africa, where a local pilot was brought on board who guided them across the Indian
Time in Portugal March to last Sunday in October in the whole country.<ref name="Regional Legislative Decree 6/96/M"> Regional Legislative Decree 6/96/M (Madeira), 25 June 1996 (in Portuguese). Retrieved 26 May 2013.</ref><ref name="Regional Legislative Decree 16/96/A"> Regional Legislative Decree 16/96/A (Azores), 1 August 1996 (in Portuguese). Retrieved 26 May 2013.</ref> In 1996 Portugal adopted ISO 8601 via EN 28601 as NP EN 28601:1996. The Astronomical Observatory of Lisbon publishes the official time via the Network Time Protocol (NTP), e.g. via "ntp02.oal.ul.pt" and "ntp04.oal.ul.pt". The IANA time zone database contains 3 zones for Portugal. Columns marked with * are from the file zone.tab from the