Phases of the Moon 1.0

The program computes, for a given year and month, the istant of a selected moon's phase.
The algorithms are based on Jean Meuss's "Astronomical algorithms", and the error never
exceeds few seconds (TD). However, because of the conversion from Dinamical Time(TD) to Universal
Time(UT), error may be anywhere from 0 to 2 minutes in years between 1990 and 2020. Going far
into past or future may increase the error.
The progam correctly computes even phases that happens twice a month:
try computing the last quarter of August 2002.
As an exercise, try to find the first "Blue Moon" after December 2001 ("Blue Moon"
is the second full moon in a month; it's quite rare).
MOONPH is the main program, JGDD AND CALCPH are subroutines.
No controls are made on input data, so avoid meanigless input.
The meaning for the required phases are:
1 --> Full Moon
2 --> First Quarter
3 --> Full Moon
4 --> Last Quarter

Sergio Filippini
filippini@mclink.it


References:
Atronomical Algorithms, Jean Meuss, Willman-Bell
The Astronomical Almanac, Nautical Almanac Office


