Convert unix timestamp to julian

datedatetimejulian-datetimestamp

How can I convert from a unix timestamp (say 1232559922) to a fractional julian date (2454853.03150).

I found a website ( http://aa.usno.navy.mil/data/docs/JulianDate.php ) that performs a similar calculation but I need to do it programatically.

Solutions can be in C/C++, python, perl, bash, etc…

Best Solution

The Unix epoch (zero-point) is January 1, 1970 GMT. That corresponds to the Julian day of 2440587.5

So, in pseudo-code:

function float getJulianFromUnix( int unixSecs )
{
   return ( unixSecs / 86400.0 ) + 2440587.5;
}