Extends Class DateTime agar memberikan format penamaan hari dan bulan dalam bahasa Indonesia.

IndonesiaDateTime.php

<?php

/**
 * IndonesiaDateTime.
 *
 * Extends Class DateTime agar memberikan format penamaan hari dan bulan dalam
 * bahasa Indonesia.
 *
 * @author: IjorTengab
 * @last_update: 2020 11 14
 *
 * Contoh 1, Print Format:
 * ```
 * $a = new DateTime;
 * $x = new IndonesiaDateTime;
 * echo $a->format('l'); // return Saturday
 * echo $x->format('l'); // return Sabtu
 * ```
 *
 * Contoh 2, Comparison:
 * ```
 * $a = new DateTime('yesterday');
 * $b = new DateTime('tomorrow');
 * var_dump($a < $b); // return true
 *
 * $x = new IndonesiaDateTime('yesterday');
 * $y = new IndonesiaDateTime('tomorrow');
 * var_dump($x < $y); // return true
 *
 * $a = new DateTime('yesterday');
 * $x = new IndonesiaDateTime('tomorrow');
 * var_dump($a < $x); // return true
 * ```
 *
 * Contoh 3, Minggu dan Ahad:
 * ```
 * $x = new IndonesiaDateTime('this Sunday');
 * echo $x->format('l'); // Minggu
 * $x->ahadSwitch(true);
 * echo $x->format('l'); // Ahad
 * $x->ahadSwitch(false);
 * echo $x->format('l'); // Minggu
 *
 * $y = new IndonesiaDateTime('this Sunday');
 * echo $y->format('D'); // Min
 * $y->ahadSwitch(true);
 * echo $y->format('D'); // Aha
 * $y->ahadSwitch(false);
 * echo $y->format('D'); // Min
 * ```
 */
class IndonesiaDateTime extends \DateTime
{

    /**
     * Property sebagai penanda menggunakan diksi Ahad alih-alih Minggu.
     */
    protected $ahad_switch = false;

    /**
     * Convert format dengan menutupi tiap placeholder dengan kurung kotak.
     * Berguna untuk mencegah salah translate antara Mon dan Monday yang
     * mengandung substring `Mon`.
     */
    protected $converter = [
        'D' => '[D]',
        'l' => '[l]',
        'F' => '[F]',
        'M' => '[M]',
    ];

    /**
     * Translate kata.
     */
    protected $replacement = [
        '[Sun]' => 'Min',
        '[Mon]' => 'Sen',
        '[Tue]' => 'Sel',
        '[Wed]' => 'Rab',
        '[Thu]' => 'Kam',
        '[Fri]' => 'Jum',
        '[Sat]' => 'Sab',
        '[Sunday]' => 'Minggu',
        '[Monday]' => 'Senin',
        '[Tuesday]' => 'Selasa',
        '[Wednesday]' => 'Rabu',
        '[Thursday]' => 'Kamis',
        '[Friday]' => 'Jumat',
        '[Saturday]' => 'Sabtu',
        '[Jan]' => 'Jan',
        '[Feb]' => 'Feb',
        '[Mar]' => 'Mar',
        '[Apr]' => 'Apr',
        '[May]' => 'Mei',
        '[Jun]' => 'Jun',
        '[Jul]' => 'Jul',
        '[Aug]' => 'Agu',
        '[Sep]' => 'Sep',
        '[Oct]' => 'Okt',
        '[Nov]' => 'Nov',
        '[Dec]' => 'Des',
        '[January]' => 'Januari',
        '[February]' => 'Februari',
        '[March]' => 'Maret',
        '[April]' => 'April',
        '[May]' => 'Mei',
        '[June]' => 'Juni',
        '[July]' => 'Juli',
        '[August]' => 'Agustus',
        '[September]' => 'September',
        '[October]' => 'Oktober',
        '[November]' => 'November',
        '[December]' => 'Desember',
    ];

    /**
     * Fungsi untuk turn on/off pemilihan format Ahad alih-alih Minggu.
     */
    public function ahadSwitch($boolean)
    {
        return $this->ahad_switch = $boolean;
    }

    /**
     * Sama seperti DateTime::format. Disini akan di-translate kata dalam bahasa
     * English ke Indonesia.
     */
    public function format($format)
    {
        $format = strtr($format, $this->converter);
        $result = parent::format($format);
        $replacement = $this->replacement;
        if ($this->ahad_switch) {
            $replacement['[Sun]'] = 'Aha';
            $replacement['[Sunday]'] = 'Ahad';
        }
        return strtr($result, $replacement);
    }

    public static function createFromFormat($format, $datetime, $timezone = null) {
        return new static((\DateTime::createFromFormat($format, $datetime, $timezone))->format('c'));
    }
}

<?php
// Variable.
$year = date('Y');
// Process.
$yearCurrent = IndonesiaDateTime::createFromFormat('Y-m-d', $year.'-01-01');
$yearCurrent->modify('midnight');
$yearCurrent->ahadSwitch(true);
$yearNext = IndonesiaDateTime::createFromFormat('Y-m-d', ($year + 1) .'-01-01');
$yearNext->modify('midnight');
while ($yearCurrent < $yearNext) {
    echo $yearCurrent->format('Y m d l:');
    echo PHP_EOL;
    $yearCurrent->modify('+1 day');
    // break;
}

Command line version.

<?php
require "IndonesiaDateTime.php";

// Variable.
$year = isset($_SERVER['argv']['1']) ? $_SERVER['argv']['1'] : date('Y');

// Process.
$yearCurrent = IndonesiaDateTime::createFromFormat('Y-m-d', $year.'-01-01');
$yearCurrent->modify('midnight');
$yearCurrent->ahadSwitch(true);
$yearNext = IndonesiaDateTime::createFromFormat('Y-m-d', ($year + 1) .'-01-01');
$yearNext->modify('midnight');
while ($yearCurrent < $yearNext) {
    echo $yearCurrent->format('Ymd l:');
    echo PHP_EOL;
    $yearCurrent->modify('+1 day');
    // break;
}