Moon-phases

I made a calendar-lib while ago and it works pretty nice.

But I never got around to calculate moon-phases correctly.

What I want is to know the exact phase of the moon at any
given day in the gregorian calendar. (or between 1900 and 2099-ish...)

I'd be extremely happy if anyone could point me in the
correct direction.

up?




http://www.calculatorcat.com/moon_phases/moon_phases.phtml
http://aa.usno.navy.mil/faq/docs/moon_phases.php
http://www.metta.org.uk/yoga/moon_phase.asp

http://stardate.org/nightsky/moon/

Better one:

http://www.paulcarlisle.net/mooncalendar/

Requires JAVA

Sorry, the first one only goes back to 1951. Shouldn't you be able to calculate further back though?

EDIT: Posted a second one which goes wayyyyyyyyyyyyyyyy back to 3999 BC

Have a look at www.astro.com - it's an astrology site but they have an swiss ephemeris for programmers - it contains code which you can use (various licences) to accurately calculate the positions of any planets, moons, asteriods etc over thousands of years.

Moon-phases? wedoe are you making a werewolf reminder/forecasting program?

Thanks all but I need the formula not a website, but it
seems I maybe can use something from astro.com, thanks
a lot "Imaginary Human" :o)

Very complex stuff tho, but I'll find a way ;)

Duffer: Good idea ;o)

Well, there's a number of websites which calculate the current phase and it's probably not accurate to anything more than the nearest hour or even day, so you could just say okay today the phase is at 54% and then start counting moon cycles.

I thought about that but being a perfectionist,
it would not feel as good as a flawless algoritm.

http://home.att.net/~srschmitt/script_moon_phase.html

It's a very simple lunar phase calculator. No idea how accurate it is over long time periods. The code is JavaScript and the author says it can be freely used. Just "View Source" in your browser.

Thanks a million Floyd, this is EXACTLY what I needed, hurray ! :D

You know that feeling when the last piece in the puzzle
is put into place - bliss.....