wpseek.com
A WordPress-centric search engine for devs and theme authors

function date_i18n( $dateformatstring, $timestamp_with_offset = false, $gmt = false ) {
	global $wp_locale;
	$i = $timestamp_with_offset;

	if ( false === $i ) {
		$i = current_time( 'timestamp', $gmt );
	}

	/*
	 * Store original value for language with untypical grammars.
	 * See https://core.trac.wordpress.org/ticket/9396
	 */
	$req_format = $dateformatstring;

	$dateformatstring = preg_replace( '/(?<!\\\\)c/', DATE_W3C, $dateformatstring );
	$dateformatstring = preg_replace( '/(?<!\\\\)r/', DATE_RFC2822, $dateformatstring );

	if ( ( ! empty( $wp_locale->month ) ) && ( ! empty( $wp_locale->weekday ) ) ) {
		$datemonth            = $wp_locale->get_month( gmdate( 'm', $i ) );
		$datemonth_abbrev     = $wp_locale->get_month_abbrev( $datemonth );
		$dateweekday          = $wp_locale->get_weekday( gmdate( 'w', $i ) );
		$dateweekday_abbrev   = $wp_locale->get_weekday_abbrev( $dateweekday );
		$datemeridiem         = $wp_locale->get_meridiem( gmdate( 'a', $i ) );
		$datemeridiem_capital = $wp_locale->get_meridiem( gmdate( 'A', $i ) );
		$dateformatstring     = ' ' . $dateformatstring;
		$dateformatstring     = preg_replace( '/([^\\\])D/', "\\1" . backslashit( $dateweekday_abbrev ), $dateformatstring );
		$dateformatstring     = preg_replace( '/([^\\\])F/', "\\1" . backslashit( $datemonth ), $dateformatstring );
		$dateformatstring     = preg_replace( '/([^\\\])l/', "\\1" . backslashit( $dateweekday ), $dateformatstring );
		$dateformatstring     = preg_replace( '/([^\\\])M/', "\\1" . backslashit( $datemonth_abbrev ), $dateformatstring );
		$dateformatstring     = preg_replace( '/([^\\\])a/', "\\1" . backslashit( $datemeridiem ), $dateformatstring );
		$dateformatstring     = preg_replace( '/([^\\\])A/', "\\1" . backslashit( $datemeridiem_capital ), $dateformatstring );

		$dateformatstring = substr( $dateformatstring, 1, strlen( $dateformatstring ) - 1 );
	}
	$timezone_formats    = array( 'P', 'I', 'O', 'T', 'Z', 'e' );
	$timezone_formats_re = implode( '|', $timezone_formats );
	if ( preg_match( "/$timezone_formats_re/", $dateformatstring ) ) {
		$timezone_string = get_option( 'timezone_string' );
		if ( false === $timestamp_with_offset && $gmt ) {
			$timezone_string = 'UTC';
		}
		if ( $timezone_string ) {
			$timezone_object = timezone_open( $timezone_string );
			$date_object     = date_create( null, $timezone_object );
			foreach ( $timezone_formats as $timezone_format ) {
				if ( false !== strpos( $dateformatstring, $timezone_format ) ) {
					$formatted        = date_format( $date_object, $timezone_format );
					$dateformatstring = ' ' . $dateformatstring;
					$dateformatstring = preg_replace( "/([^\\\])$timezone_format/", "\\1" . backslashit( $formatted ), $dateformatstring );
					$dateformatstring = substr( $dateformatstring, 1, strlen( $dateformatstring ) - 1 );
				}
			}
		} else {
			$offset = get_option( 'gmt_offset' );
			foreach ( $timezone_formats as $timezone_format ) {
				if ( 'I' === $timezone_format ) {
					continue;
				}

				if ( false !== strpos( $dateformatstring, $timezone_format ) ) {
					if ( 'Z' === $timezone_format ) {
						$formatted = (string) ( $offset * HOUR_IN_SECONDS );
					} else {
						$prefix    = '';
						$hours     = (int) $offset;
						$separator = '';
						$minutes   = abs( ( $offset - $hours ) * 60 );

						if ( 'T' === $timezone_format ) {
							$prefix = 'GMT';
						} elseif ( 'e' === $timezone_format || 'P' === $timezone_format ) {
							$separator = ':';
						}

						$formatted = sprintf( '%s%+03d%s%02d', $prefix, $hours, $separator, $minutes );
					}

					$dateformatstring = ' ' . $dateformatstring;
					$dateformatstring = preg_replace( "/([^\\\])$timezone_format/", "\\1" . backslashit( $formatted ), $dateformatstring );
					$dateformatstring = substr( $dateformatstring, 1 );
				}
			}
		}
	}
	$j = @gmdate( $dateformatstring, $i );

	/**
	 * Filters the date formatted based on the locale.
	 *
	 * @since 2.8.0
	 *
	 * @param string $j          Formatted date string.
	 * @param string $req_format Format to display the date.
	 * @param int    $i          A sum of Unix timestamp and timezone offset in seconds.
	 * @param bool   $gmt        Whether to use GMT timezone. Only applies if timestamp was
	 *                           not provided. Default false.
	 */
	$j = apply_filters( 'date_i18n', $j, $req_format, $i, $gmt );
	return $j;
}