Navigators used tables to determine the longitude that depend on the day. The theory[0] is that because their flight involved multiple day changes, Noonan might

Navigators used tables to determine the longitude that depend on the day. The theory[0] is that because their flight involved multiple day changes, Noonan might've done some on the fly calculation that plugged star positions into the wrong day's table, putting them off by 1 degree of longitude. [0]: http://www.datelinetheory.com/ http://www.datelinetheory.com/, no idea how plausible this is