Lunar calendar or crescent moons and others employing detailed calculations. Since each lunation is approximately days (29 days, 12 hours, 44 minutes, 3 seconds, or days), it is common for the months of a lunar calendar to alternate between 29 and 30 days. Since the period of twelve such lunations, a lunar year, is only 354 days, 8 hours, 48 minutes, 34 seconds ( days), purely lunar calendars lose around 11 days per year relative to the Gregorian calendar. In purely lunar calendars like the Islamic calendar, the lack of intercalation causes the lunar months to cycle through all the seasons of
America-class steamship "Europa" was also chartered as a troopship during the Crimean War and continued in Cunard service until 1867, when she was sold and converted to a sailing ship. Won the eastbound record in 1849 with a Halifax–Liverpool voyage of 8 days 12 hours 44 minutes, an average of . During the Crimean War, she remained on the Halifax route and was sold for conversion to a sailing ship in 1866. Took the Blue Riband in May 1850 with a Liverpool–Halifax run of 8 days 14 hours 50 minutes, an average of . "Asia" also remained on the Halifax route during