Extends DateTimePlus(). This class extends the basic component and adds in Drupal-specific handling, like translation of the format() method

public DateFormatInterface::setPattern($pattern)

protected DateFormatter::dateFormat($format, $langcode)

The request stack. Type: \Symfony\Component\HttpFoundation\RequestStack File

A computed property for dates of date time field items. Required settings (below the definition's 'settings' key) are:

public static DateHelper::weekDaysAbbr1($required = FALSE)

public DateFormatter::getSampleDateFormats($langcode = NULL, $timestamp

public static DateHelper::daysInYear($date = NULL)

public static Datelist::processDatelist(&$element, FormStateInterface

public static DateTimePlus::arrayToISO($array, $force_valid_date = FALSE)