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jdtounix

(PHP 4, PHP 5)

jdtounixConvert Julian Day to Unix timestamp

Descrierea

int jdtounix ( int $jday )

This function will return a Unix timestamp corresponding to the Julian Day given in jday or FALSE if jday is not inside the Unix epoch (Gregorian years between 1970 and 2037 or 2440588 <= jday <= 2465342 ). The time returned is localtime (and not GMT).

Parametri

jday

A julian day number between 2440588 and 2465342.

Valorile întoarse

The unix timestamp for the start of the given julian day.

Vedeți de asemenea

  • unixtojd() - Convert Unix timestamp to Julian Day

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User Contributed Notes 4 notes

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fabio at llgp dot org
8 years ago
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
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Anonymous
9 years ago
Warning: 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!!
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seb at carbonauts dot com
11 years ago
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.
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pipian at pipian dot com
11 years ago
Remember that UNIX timestamps indicate a number of seconds from midnight of January 1, 1970 on the Gregorian calendar, not the Julian Calendar.
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