Book excerpt: The Air Almanac 2018 contains the astronomical data required for air celestial navigation, making it a necessary resource for all pilots and others attempting to chart routes based on celestial bodies. This edition of the Almanac includes information for the year 2018 on the following topics: Sunrise, sunset, and twilight tables Sky diagrams for each month Rise and set times of the Moon for a range of latitudes Positions of the navigational stars The Almanac also provides the Greenwich hour angle and declination of the Sun, Moon, and three navigational planets along with the Greenwich hour angle of Aries, all tabulated at 10-minute intervals. With all of this data organized into two pages per calendar day, this new paperback edition provides comprehensive, organized navigational information for each day of the year.