| Documentation

MoonPhase

new MoonPhase()

Instance Members

▸ flmoon(n, nph)

flmoon() calculates the julian date of nth lunar cycle and nph phase of the moon since Jan 1900 n is the number of lunar cycle since Jan 1900 - ??? This is the original function from the book. It's been modified to work in JavaScript. I also rewrote it to be litte clearer. And added comments where I unterstood what was going on and increased the accuracy of a few constants.

flmoon(n: number, nph: number): number

Parameters

n (number) The number of lunar cycles.

nph (number) The lunar phase.

Returns

number: The full Julian date of the nth lunar cycle plus nph phase Note that the integer and fractional parts are returned by references.

▸ nextphase(year, mon, day, hr, min, nph, jd)

Julian2Calendar() computes the julian date

nextphase(year: number, mon: number, day: number, hr: any, min: any, nph: any, jd: number): number

Parameters

year (number) The year.

mon (number) The month.

day (number) The day of the month.

hr (any)

min (any)

nph (any)

jd (number) The Julian date number.

Returns

number: Note that all the return values are references.

▸ isDST(date)

isDST() returns true if the given date is day light savings time There are two versions, one which takes the Julian date and one that takes the monuth, day and year.

isDST(date: Date): boolean

Parameters

date (Date) The date

Returns

boolean:

▸ Julian2Calendar(jd, mon, day, year)

Julian2Calendar() computes the julian date

Julian2Calendar(jd: number, mon: number, day: number, year: number): any

Parameters

jd (number) The Julian date number.

mon (number) The month.

day (number) The day of the month.

year (number) The year.

Returns

any: Note that all the return values are references.

▸ Calendar2Julian(year, month, day, mon)

calendar2Julian() computes the date given a julian date

Calendar2Julian(year: number, month: any, day: number, mon: number)

Parameters

year (number) The year.

month (any)

day (number) The day of the month.

mon (number) The month.

sun_anomaly

Sun's mean anomaly

sun_anomaly

moon_anomaly

Moon's mean anomaly

moon_anomaly

xtra

Not sure of what's up here, but two of the numbers very interesting Notice that 2415020.75933 is used a referce epochs for mean time of lunar cycle which is 1900 Jan 1 at 6:13 AM And 29.53058868 is the "Synodic month" or the mean time in days between new moons.

xtra

Looks like this is all being done to adjust the variations in the maen lunar cycle of 29.53058868 Which from what I understand is due the moons orbit in relationship to the earths orbit around the sun.

xtra

jd

Ok 2415020 is Julian date 1899 at noon + .75933 is the Julian date of a new moon 28 + 1.53058868 is mean time of a lunar cycle , and 7 close to 7.38264717 a lunar phase but unlike the first two the tractional part dose not seem to be accounted for.

jd

int_part

This parts easy just put the integer and fractional parts right

int_part

n

12.37 is the number of lunar cycles per year n then is the number of lunar cycles since 1900 and the year month entered

n