Sec. 73.1720  Daytime.

    Operation is permitted during the hours between average monthly 
local sunrise and average monthly local sunset.
    (a) The controlling times for each month of the year are stated in 
the station's instrument of authorization. Uniform sunrise and sunset 
times are specified for all of the days of each month, based upon the 
actual times of sunrise and sunset for the fifteenth day of the month 
adjusted to the nearest quarter hour. Sunrise and sunset times are 
derived by using the standardized procedure and the tables in the 1946 
American Nautical Almanac issued by the United States Naval Observatory.
    (b) [Reserved]

[ 43 FR 45849 , Oct. 4, 1978]