Umland's Java Script Almanac

[Bi111ion]

Henning Umland wrote a really handy Long term almanac for the Sun and Moon
http://www.celnav.de/longterm.htm
in Javascript. It is handy as you can download the same thing on any device with browser, boat computer, phone tablet and use it for celestial navigation.

Unfortunately it was giving the wrong answer due to a change in the trunc function in javascript.

Over on NavList http://fer3.com/arc/m2.aspx/Henning-Umlands-long-term-almanac-it-wrong-FrankReed-feb-2016-g34758 Frank Reed has fixed this and has recently got in touch with Henning who has updated his page.

I thought it was worth mentioning as like me you might have old copies downloaded and you need to update them and check them. I only spotted the mistake when practising at home and my garden seemed to have moved several 10s of nautical miles.

 

[oldvarnish]

Henning Umland wrote a really handy Long term almanac for the Sun and Moon
http://www.celnav.de/longterm.htm

Very useful site, thanks for posting.

Does it work within the Javascript, or do you need to be online for it to function?

 

[Bi111ion]

You just (eg in Mozilla) "save page". All the code is in the web pages so runs off-line. That is the whole point, javascript while a horrible language is one that is most likely to be implemented on your device. I am thinking of it as the new equivalent of the old navigation programmable calculator. So your back up might be a cheap waterproofed phone and a solar charger for it. So all I need (post navigation satellite Armageddon), is a tall ship, a javascript capable phone, a solar charger, and a sextant.

 

[oldvarnish]

You just (eg in Mozilla) "save page". All the code is in the web pages so runs off-line. That is the whole point, javascript while a horrible language is one that is most likely to be implemented on your device. I am thinking of it as the new equivalent of the old navigation programmable calculator. So your back up might be a cheap waterproofed phone and a solar charger for it. So all I need (post navigation satellite Armageddon), is a tall ship, a javascript capable phone, a solar charger, and a sextant.

Understood - thanks