Then, see how many degrees is corrected lunar anomaly. If it
is less than 180°, subtract visible anomaly of this corrected anomaly from the
mean lunar longitude the observation time. And if corrected lunar anomaly is
more than 180° but less than 360°, add visible anomaly of this corrected anomaly
to the mean lunar longitude the observation time. And mean lunar longitude after
you add to it or subtract from it is the
*true lunar longitude at the observation time*.