Method getInput

/**
 * Method to get the field input markup.
 *
 * @return  string  The field input markup.
 *
 * @since   1.7.0
 */
protected function getInput()
{
    $user = Factory::getApplication()->getIdentity();
    // If a known filter is given use it.
    switch (strtoupper($this->filter)) {
        case 'SERVER_UTC':
            // Convert a date to UTC based on the server timezone.
            if ($this->value && $this->value != Factory::getDbo()->getNullDate()) {
                // Get a date object based on the correct timezone.
                $date = Factory::getDate($this->value, 'UTC');
                $date->setTimezone(new \DateTimeZone(Factory::getApplication()->get('offset')));
                // Transform the date string.
                $this->value = $date->format('Y-m-d H:i:s', true, false);
            }
            break;
        case 'USER_UTC':
            // Convert a date to UTC based on the user timezone.
            if ($this->value && $this->value != Factory::getDbo()->getNullDate()) {
                // Get a date object based on the correct timezone.
                $date = Factory::getDate($this->value, 'UTC');
                $date->setTimezone($user->getTimezone());
                // Transform the date string.
                $this->value = $date->format('Y-m-d H:i:s', true, false);
            }
            break;
    }
    // Format value when not nulldate ('0000-00-00 00:00:00'), otherwise blank it as it would result in 1970-01-01.
    if ($this->value && $this->value != Factory::getDbo()->getNullDate() && strtotime($this->value) !== false) {
        $tz = date_default_timezone_get();
        date_default_timezone_set('UTC');
        if ($this->filterFormat) {
            $date = \DateTimeImmutable::createFromFormat('U', strtotime($this->value));
            $this->value = $date->format($this->filterFormat);
        } else {
            $this->value = strftime($this->format, strtotime($this->value));
        }
        date_default_timezone_set($tz);
    } else {
        $this->value = '';
    }
    return $this->getRenderer($this->layout)->render($this->getLayoutData());
}