1.1  The Sunrise/Sunset times are prepared based on the information produced by Institute of Astronomy and Geophysics, Mongolian Academy of Sciences.

1.2  Time for the beginning of morning civil twilight, sunrise, sunset and time for the end of evening civil twilight are published by AIP Supplement (AIP SUP) every year. The times in the AIP Supplement are calculated by the coordinates of each Aerodrome Reference Point and given in Coordinated Universal Time (UTC) along with the conversion method to Local Time (LT) and Ulaanbaatar time (ULAT).