README

SunCalc PHP is a tiny PHP library for calculating sun position, sunlight phases (times for sunrise, sunset, dusk, etc.), moon position, and lunar phase for a given location and time. This fork brings the original gregseth/suncalc-php library up to PHP 8, publishes it as a modern Composer package, and keeps full API compatibility with the original JavaScript library created by Vladimir Agafonkin (@mourner).

Most calculations are based on the formulas given in the excellent Astronomy Answers articles about the position of the sun and the planets. You can read about the different twilight phases calculated by SunCalc in the Twilight article on Wikipedia.

Requirements

• PHP ^8.0
• ext-date (enabled by default on most PHP installations)

Installation

Install the package via Composer:

composer require tuxonice/suncalc-php

Once installed, the library is available under the Tlab\\SunCalc namespace via PSR-4 autoloading.

Usage example

<?php

use Tlab\SunCalc\SunCalc;

$sunCalc = new SunCalc(new DateTimeImmutable('now', new DateTimeZone('Europe/Paris')), 48.85, 2.35);

// Format sunrise time from the DateTime object
$sunTimes = $sunCalc->getSunTimes();
$sunriseStr = $sunTimes['sunrise']->format('H:i');

// Get position of the sun (azimuth and altitude) at today's sunrise
$sunrisePos = $sunCalc->getPosition($sunTimes['sunrise']);

// Get sunrise azimuth in degrees
$sunriseAzimuth = $sunrisePos->azimuth * 180 / M_PI;

Reference

Sunlight times

SunCalc::getSunTimes()

Returns an array with the following indexes (each is a DateTime object):

SunCalc::times property contains all currently defined times.

Sun position

SunCalc::getSunPosition(/*DateTime*/ $timeAndDate)

Returns an object with the following properties:

• altitude: sun altitude above the horizon in radians, e.g. 0 at the horizon and PI/2 at the zenith (straight over your head)
• azimuth: sun azimuth in radians (direction along the horizon, measured from south to west), e.g. 0 is south and M_PI * 3/4 is northwest

Moon position

SunCalc::getMoonPosition(/*DateTime*/ $timeAndDate)

Returns an object with the following properties:

• altitude: moon altitude above the horizon in radians
• azimuth: moon azimuth in radians
• distance: distance to moon in kilometers

Moon illumination

SunCalc::getMoonIllumination()

Returns an array with the following properties:

• fraction: illuminated fraction of the moon; varies from 0.0 (new moon) to 1.0 (full moon)
• phase: moon phase; varies from 0.0 to 1.0, described below
• angle: midpoint angle in radians of the illuminated limb of the moon reckoned eastward from the north point of the disk; the moon is waxing if the angle is negative, and waning if positive

Moon phase value should be interpreted like this:

Moon rise and set times

SunCalc::getMoonTimes($inUTC)

Returns an object with the following indexes:

• rise: moonrise time as DateTime
• set: moonset time as DateTime
• alwaysUp: true if the moon never rises/sets and is always above the horizon during the day
• alwaysDown: true if the moon is always below the horizon

By default, it will search for moon rise and set during local user's day (from 0 to 24 hours). If $inUTC is set to true, it will instead search the specified date from 0 to 24 UTC hours.

What changed in this fork

• Upgraded the codebase to require PHP 8.0 or newer and leverage modern language features such as typed properties and strict typing.
• Published under the package name tuxonice/suncalc-php with PSR-4 autoloading for the Tlab\\SunCalc\\ namespace.
• Added tooling for development (PHPUnit, PHP_CodeSniffer, PHPStan) to keep the implementation consistent and reliable.

Development

1. Install dependencies:

   composer install

2. Run the test suite:

   vendor/bin/phpunit

3. (Optional) Run static analysis and coding standards:

   vendor/bin/phpstan analyse
   vendor/bin/phpcs

Credits

• Original JavaScript algorithm by Vladimir Agafonkin
• Original PHP port by Greg Seth
• PHP 8 refactor and Composer package by Helder Correia

License

Released under the GPLv2 license. See the LICENSE file for details.