def describe_maintenance_start_time(GatewayARN=None):
    """
    Returns your gateway's weekly maintenance start time including the day and time of the week. Note that values are in terms of the gateway's time zone.
    See also: AWS API Documentation
    
    Examples
    Returns your gateway's weekly maintenance start time including the day and time of the week.
    Expected Output:
    
    :example: response = client.describe_maintenance_start_time(
        GatewayARN='string'
    )
    
    
    :type GatewayARN: string
    :param GatewayARN: [REQUIRED]
            The Amazon Resource Name (ARN) of the gateway. Use the ListGateways operation to return a list of gateways for your account and region.
            

    :rtype: dict
    :return: {
        'GatewayARN': 'string',
        'HourOfDay': 123,
        'MinuteOfHour': 123,
        'DayOfWeek': 123,
        'Timezone': 'string'
    }
    
    
    """
    pass
