Downtime-Uptime

Hi,

I´m using sql query below to get this data:

SELECT
    StartTime.EventTime,
    Nodes.Caption,
    Nodes.Location,
    StartTime.Message,
    DATEDIFF(Mi, StartTime.EventTime,
    (SELECT TOP 1
        EventTime
        FROM Events AS Endtime
        WHERE EndTime.EventTime > StartTime.EventTime AND EndTime.EventType = 5
            AND EndTime.NetObjectType = 'N'
            AND EndTime.NetworkNode = StartTime.NetworkNode
        ORDER BY EndTime.EventTime)) AS OutageDurationInMinutes

FROM Events StartTime INNER JOIN Nodes ON StartTime.NetworkNode = Nodes.NodeID
WHERE link = 1 and  (StartTime.EventType = 1) AND (StartTime.NetObjectType = 'N') AND
eventtime between dateadd(month, -1, getdate()) and getdate()
/*
ORDER BY Nodes.Caption ASC
*/
order by StartTime.EventTime

How could I change this query to show me the "Uptime" too ?

Thanks