If you need an easy way to convert a decimal julian day to an unix timestamp you can use:
$unixTimeStamp = ($julianDay - 2440587.5) * 86400;
2440587.5 is the julian day at 1/1/1970 0:00 UTC
86400 is the number of seconds in a day
(PHP 4, PHP 5, PHP 7, PHP 8)
jdtounix — Convierte un día Juliano en un timestamp UNIX
Devuelve un timestamp UNIX correspondiente al día Juliano
julian_day o false si julian_day
no está dentro del intervalo permitido. El tiempo devuelto es UTC.
julian_day
El número de días Julianos, comprendido entre
2440588 y 106751993607888 en
sistemas de 64 bits, o comprendido entre
2440588 y 2465443 en sistemas
de 32 bits.
El timestamp UNIX para el inicio (medianoche, no mediodía) del día Juliano dado.
Si julian_day está fuera del intervalo permitido,
se lanza una ValueError.
| Versión | Descripción |
|---|---|
| 8.0.0 |
Esta función ya no devuelve false en caso de error,
sino que lanza una ValueError en su lugar.
|
| 7.3.24, 7.4.12 |
El límite superior del parámetro julian_day ha sido
extendido. Antes, era de 2465342 según la arquitectura.
|
If you need an easy way to convert a decimal julian day to an unix timestamp you can use:
$unixTimeStamp = ($julianDay - 2440587.5) * 86400;
2440587.5 is the julian day at 1/1/1970 0:00 UTC
86400 is the number of seconds in a dayWarning: the calender functions involving julian day operations seem to ignore the decimal part of the julian day count.
This means that the returned date is wrong 50% of the time, since a julian day starts at decimal .5 . Take care!!Remember that unixtojd() assumes your timestamp is in GMT, but jdtounix() returns a timestamp in localtime.
This fooled me a few times.
So if you have:
$timestamp1 = time();
$timestamp2 = jdtounix(unixtojd($timestamp1));
Unless your localtime is the same as GMT, $timestamp1 will not equal $timestamp2.Remember that UNIX timestamps indicate a number of seconds from midnight of January 1, 1970 on the Gregorian calendar, not the Julian Calendar.unixtojd() assumes that your timestamp is in GMT, but jdtounix() returns a timestamp in localtime.
so
<?php
$d1=jdtogregorian(unixtojd(time()));
$d2= gmdate("m/d/Y");
$d3=date("m/d/Y");
?>
$d1 always equals $d2 but $d1 may differ from $d3