You can now localize DateTime::format()

BetterDateTime.php

<?php

class BetterDateTime extends DateTime {
	private $dictFormatToStrf = array (
		"d" => "%d",
		"D" => "%a",
		"j" => "_nt-dm_", //%e
		"l" => "%A",
		"N" => "%u",
		"S" => "_suffix_",
		"w" => "%w",
		"z" => "_nt-dy_", //%j
		"W" => "%W", //%W
		"F" => "%B",
		"m" => "%m",
		"M" => "%h",
		"n" => "_nt-m_",
		"t" => "_daysinmonth_",
		"L" => "_leapyear_",
		"o" => "_prevweekyear_",
		"Y" => "%Y",
		"y" => "%y",
		"a" => "%p",
		"A" => "%P",
		"B" => "_swatch_",
		"g" => "%l",
		"G" => "%k",
		"h" => "%I",
		"H" => "%H",
		"i" => "%M",
		"s" => "%S",
		"u" => "_microseconds_",
		"e" => "%Z",
		"I" => "_dst_",
		"O" => "%z",
		"P" => "_zwithcolon_",
		"T" => "_abbrtimezone_",
		"Z" => "_zinseconds_",
		"c" => "%Y-%m-%dT%H:%M:%S_zwithcolon_",
		"r" => "%a, _nt-dm_ %b %Y %H:%M:%S %z",
		"U" => "_unix_"
	);

	private $notSupported = array(
		"_nt-dm_", 
		"_suffix_", 
		"_nt-dy_", 
		"_nt-m_", 
		"_daysinmonth_", 
		"_leapyear_", 
		"_prevweekyear_", 
		"_swatch_", 
		"_microseconds_",
		"_dst_",
		"_zwithcolon_",
		"_abbrtimezone_",
		"_zinseconds_",
		"_unix_"
	);

	private function _formatToStrf ($format) {
		$formatComponents = str_split($format);
		$newComponents = array();
		$prevComponent = "";
		foreach($formatComponents as $component) {
			if (array_key_exists($component, $this->dictFormatToStrf) && $prevComponent != "\\") {
				array_push($newComponents, $this->dictFormatToStrf[$component]);
			} else {
				array_push($newComponents, $component);
			}

			$prevComponent = $component;
		}
		

		$newFormat = implode("",$newComponents);
		return str_replace("\\","",$newFormat);
	}

	public function localizedFormat ($format, $locale = false) {
		$newFormat = $this->_formatToStrf($format);
		if($locale) {
			$prevLocale = setlocale(LC_TIME, '0');
			setLocale(LC_TIME,$locale);
		}
		$dateString = strftime($newFormat,$this->getTimestamp());
		if($locale) {
			setLocale(LC_TIME,$prevLocale);
		}

		foreach($this->notSupported as $target) {
			$dateString = str_replace($target, $this->format(array_search($target,$this->dictFormatToStrf)),$dateString);
		}

		return $dateString;


	}
}

$testDate = new BetterDateTime();

echo $testDate->format('D j F Y H:i:s') . "<br />";
echo $testDate->localizedFormat('D j F Y H:i:s','en') . "<br />";
echo $testDate->localizedFormat('D j F Y H:i:s','de') . "<br />";
echo $testDate->localizedFormat('D j F Y H:i:s','es') . "<br />";
echo $testDate->localizedFormat('D j F Y H:i:s','fr') . "<br />";
echo $testDate->localizedFormat('D j F Y H:i:s','no') . "<br />";
echo $testDate->localizedFormat('r','pt') . "<br />";
echo $testDate->localizedFormat('c','da') . "<br />";