Convert local datetime and/or datetime without timezone information to UTC datetime with timezone
	information.

	:param dt: local datetime to convert. If is None, then system datetime value is used
	:param local_value: whether dt is a datetime in system timezone or UTC datetime without timezone information
	:return: datetime in UTC with tz set

def utc_datetime(dt=None, local_value=True):
	""" Convert local datetime and/or datetime without timezone information to UTC datetime with timezone
	information.

	:param dt: local datetime to convert. If is None, then system datetime value is used
	:param local_value: whether dt is a datetime in system timezone or UTC datetime without timezone information
	:return: datetime in UTC with tz set
	"""
	# TODO: rename local_value to local_tz or in_local_tz
	if dt is None:
		return datetime.now(tz=timezone.utc)

	result = dt
	if result.utcoffset() is None:
		if local_value is False:
			return result.replace(tzinfo=timezone.utc)
		else:
			result = result.replace(tzinfo=local_tz())

	return result.astimezone(timezone.utc)