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
Iditarod Trail Sled Dog Race Seavey with a time of 8 days, 11 hours, 20 minutes, and 16 seconds. As of 2012, Dallas Seavey was also the youngest musher to win the race at the age of 25. In 2017, at the age of 57, Dallas's father, Mitch Seavey, is the oldest and fastest person ever to win the race, crossing the line in Nome in 8 days, 3 hours, 40 minutes and 13 seconds. Dallas finished second, two hours and 44 minutes behind. Teams generally race through blizzards causing whiteout conditions, sub-zero temperatures and gale-force winds which can cause the wind chill to reach