note 74199 added to function.jdtounix

Beware, jd here is not (astronomical or geocentric) Julian Day (JD), but Chronological Julian Day (CJD)! When JD start at noon of UTC time (12:00 UTC), CJD start at midnight at *local* time! Or considering head "Chronlogical Julian Day/Date" at "http://www.decimaltime.hynes.net/dates.html", when day localy start (it should be at sunset for instance). try this... <?php define("UJD", 2440587.5); define("SEC4DAY", 86400); function u2j($tm) { return $tm / SEC4DAY + UJD; } function mmd($txt, $str_time) { $t = strtotime($str_time); $j = unixtojd($t); $j_fabio = u2j($t); $s = strftime('%D %T %Z', $t); printf("${txt} => %s, CJD: %s, JD: %s<br>\n", $s, $j, $j_fabio); } $xt = strtotime("1.1.1970 0:00.00 GMT"); $slb = "-1 day 23:30"; // let CJD be N $sla = "0:30.00"; // should be N+1 $slm = "0:00"; // should be N+1 $sgmt = "0:00.00 GMT"; // don't forget to observe JD. mmd("local before", $slb); mmd("local after", $sla); mmd("local midnight", $slm); mmd("GMT midnight", $sgmt); ?> I got this (you see, JD havn't change day, because UTC noon is far away): local before => 03/28/07 23:30:00 CEST, CJD: 2454188, JD: 2454188.39583 local after => 03/29/07 00:30:00 CEST, CJD: 2454189, JD: 2454188.4375 local midnight => 03/29/07 00:00:00 CEST, CJD: 2454189, JD: 2454188.41667 GMT midnight => 03/29/07 02:00:00 CEST, CJD: 2454189, JD: 2454188.5 ---- Server IP: 212.24.129.110 Probable Submitter: 217.198.112.101 ---- Manual Page -- http://www.php.net/manual/en/function.jdtounix.php Edit -- https://master.php.net/note/edit/74199 Del: integrated -- https://master.php.net/note/delete/74199/integrated Del: useless -- https://master.php.net/note/delete/74199/useless Del: bad code -- https://master.php.net/note/delete/74199/bad+code Del: spam -- https://master.php.net/note/delete/74199/spam Del: non-english -- https://master.php.net/note/delete/74199/non-english Del: in docs -- https://master.php.net/note/delete/74199/in+docs Del: other reasons-- https://master.php.net/note/delete/74199 Reject -- https://master.php.net/note/reject/74199 Search -- https://master.php.net/manage/user-notes.php