WPCOM_JSON_API_Endpoint::parse_date PHP Method

    function parse_date($date_string)
    {
        $date_string_info = date_parse($date_string);
        if (is_array($date_string_info) && 0 === $date_string_info['error_count']) {
            // Check if it's already localized. Can't just check is_localtime because date_parse('oppossum') returns true; WTF, PHP.
            if (isset($date_string_info['zone']) && true === $date_string_info['is_localtime']) {
                $dt_local = clone $dt_utc = new DateTime($date_string);
                $dt_utc->setTimezone(new DateTimeZone('UTC'));
                return array((string) $dt_local->format('Y-m-d H:i:s'), (string) $dt_utc->format('Y-m-d H:i:s'));
            }
            // It's parseable but no TZ info so assume UTC
            $dt_local = clone $dt_utc = new DateTime($date_string, new DateTimeZone('UTC'));
        } else {
            // Could not parse time, use now in UTC
            $dt_local = clone $dt_utc = new DateTime('now', new DateTimeZone('UTC'));
        }
        // First try to use timezone as it's daylight savings aware.
        $timezone_string = get_option('timezone_string');
        if ($timezone_string) {
            $tz = timezone_open($timezone_string);
            if ($tz) {
                $dt_local->setTimezone($tz);
                return array((string) $dt_local->format('Y-m-d H:i:s'), (string) $dt_utc->format('Y-m-d H:i:s'));
            }
        }
        // Fallback to GMT offset (in hours)
        // NOTE: TZ of $dt_local is still UTC, we simply modified the timestamp with an offset.
        $gmt_offset_seconds = intval(get_option('gmt_offset') * 3600);
        $dt_local->modify("+{$gmt_offset_seconds} seconds");
        return array((string) $dt_local->format('Y-m-d H:i:s'), (string) $dt_utc->format('Y-m-d H:i:s'));
    }