MessageFormatter does not work with DateTime instances as parameters in PHP < 5.5. Instance will be converted to timestamp with value 0 (e.g. 1970-01-01) and following Notice will be raised: „Object of class DateTime could not be converted to int“. You have to manually convert the instance to timestamp in these old PHP versions.
<?php
$datetime = new DateTime();
if (PHP_VERSION_ID < 50500) { MessageFormatter::formatMessage('en_US', 'Today is {0, date, full}.', array($datetime->getTimestamp()));
} else {
MessageFormatter::formatMessage('en_US', 'Today is {0, date, full}.', array($datetime));
}
?>