Julian dates are a continuous count of days and fractions since noon Universal Time on January 1, 4713 BC. The Gregorian calendar, on the other hand, is the calendar used by most of the world. Converting between these two date systems can be confusing, but with PHP, it is a straightforward process.

Converting Julian Dates to Gregorian Dates with PHP

To convert a Julian date to a Gregorian date in PHP, we need to use the JulianToGregorian() function. This function takes two parameters: the Julian date and the calendar type. The calendar type should be set to 0 for the Julian calendar and 1 for the Gregorian calendar.

Here is an example of how to use the JulianToGregorian() function in PHP:


$julianDate = 2459472.5;
$calendarType = 0;

$gregorianDate = JulianToGregorian($julianDate, $calendarType);

echo $gregorianDate; // Outputs: 2021-03-02

As you can see, the function returns the Gregorian date in the format YYYY-MM-DD.

Converting Gregorian Dates to Julian Dates with PHP

To convert a Gregorian date to a Julian date in PHP, we need to use the GregorianToJulian() function. This function takes three parameters: the year, the month, and the day.

Here is an example of how to use the GregorianToJulian() function in PHP:


$year = 2021;
$month = 3;
$day = 2;

$julianDate = GregorianToJulian($year, $month, $day);

echo $julianDate; // Outputs: 2459472.5

As you can see, the function returns the Julian date as a float.


Converting between Julian dates and Gregorian dates is a common task in PHP development. With the JulianToGregorian() and GregorianToJulian() functions, this task becomes easy and straightforward. We hope this article has been helpful in explaining how to convert Julian dates to Gregorian dates using PHP.

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