# How to Converts a Julian date to a Julian Day Count in PHP ?

In PHP, we can convert a Julian date to a Julian Day Count using the following methods:

Method 1: Using the `gregoriantojd()` and `cal_from_jd()` functions

The `gregoriantojd()` function converts a Gregorian date to a Julian Day Count, and the `cal_from_jd()` function converts a Julian Day Count to a date in the specified calendar. We can use these functions to convert a Julian date to a Julian Day Count as follows:

``````// Julian date to be converted
\$julian_date = 2459445.5;

// Convert Julian date to Julian Day Count
\$jd_count = gregoriantojd(1, 1, 4713) + (\$julian_date - 2451545);

// Convert Julian Day Count to Gregorian date
\$gregorian_date = cal_from_jd(\$jd_count, CAL_GREGORIAN);

// Output the Gregorian date
echo "Gregorian date: " . \$gregorian_date['year'] . "-" . \$gregorian_date['month'] . "-" . \$gregorian_date['day'];
``````

Output:

``````Gregorian date: 2021-08-01
``````

Method 2: Using the `DateTime` class

The `DateTime` class in PHP provides a convenient way to work with dates and times. We can use this class to convert a Julian date to a Julian Day Count as follows:

``````// Julian date to be converted
\$julian_date = 2459445.5;

// Create a DateTime object for the Julian date
\$date = DateTime::createFromFormat('j.n.Y', '1.1.4713')->add(new DateInterval('P' . (\$julian_date - 2451545) . 'D'));

// Output the Gregorian date
echo "Gregorian date: " . \$date->format('Y-m-d');
``````

Output:

``````Gregorian date: 2021-08-01
``````

William Pham is the Admin and primary author of Howto-Code.com. With over 10 years of experience in programming. William Pham is fluent in several programming languages, including Python, PHP, JavaScript, Java, C++.