Update current date/time.

def update(self):
        """Update current date/time."""
        # Had to convert it to string because datetime is not JSON serializable
        self.stats = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        # Add the time zone (issue #1249 and issue #1337)
        if 'tmzone' in localtime():
            self.stats += ' {}'.format(localtime().tm_zone)
        elif len(tzname) > 0:
            self.stats += ' {}'.format(tzname[1])

        return self.stats