Arrival and departure dates 1862, sources?

From an old letter I have information that a ship left Norway (probably Christiania) May 3. and arrived in Quebec June 29. 1862, but the letter doesn't mention the name of the ship. On this site I don't find any ship matching these dates, but on www.theshipslist.com/ships/Arrivals/Canada1862.htm I find slightly different dates for the same ships. Therefore I wonder which sources have been used for the arrival and departure dates for the ships mentioned on this site, and does anyone know why theshipslist gives different dates? Also I see that for one of these ships (Nordlyset) there is a passenger list on this site, mentioning 30 passenger names, source Newspaper Morgenbladet July 30, 1862, but theshipslist says that the ship had 228 passengers. Therefore I wonder if the passenger list mentoned is the complete list from the newspaper or just a part of it.