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 UTC86400 is the number of seconds in a day
(PHP 4, PHP 5, PHP 7, PHP 8)
jdtounix — Converte un Giorno Giuliano in un timestamp Unix
Questa funzione restituisce un timestamp Unix corrispondente al
Giorno Giuliano giornogiuliano o false se
giornogiuliano non è all'interno della gamma Unix
(anni Gregoriani tra il 1970 e il 2037 o 2440588 <=
giornogiuliano <= 2465342 ). L'ora restituita è
locale (e non GMT).
See also unixtojd().
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 UTC86400 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