Database Maintenance Results Widget - SWQL

You should save that query as a SWQL file and then share it to the Custom Query Widget Content Exchange.

Something to note, the event ID's changed on version 2023.1 They are now 5100 and 5102 so you will need to change the query to reflect those values. 

For anyone lazy I made a quick update to the OP to include this update.  Seems like finish time stopped working but not a big deal to me if we have start and duration.

SELECT Distinct
TOLOCAL(ST.EventTime) AS [Start Time]
--,TOLOCAL(ET.EventTime) AS [Finish Time]
,CONCAT(--Downtime formatted  
        (CASE WHEN (SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60/60) >= 1 --Hours  
            THEN CONCAT(SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60/60%24, 'h ') ELSE '' END),  
        (CASE WHEN (SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60) >= 1 --Minutes  
            THEN CONCAT(SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60%60, 'm ') ELSE '' END),  
        (CASE WHEN (SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))) >= 1 --Seconds  
            THEN CONCAT(SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))%60, 's ') ELSE '' END)) AS [Duration]
FROM Orion.Events ST
LEFT JOIN Orion.Events ET ON ET.NetObjectID = ST.NetObjectID 
    AND ET.EventTime = (SELECT TOP 1 x.EventTime FROM Orion.Events x WHERE
                        x.EventTime >= ST.EventTime AND (x.EventType = 5100 OR x.EventType = 5102)
                        AND x.Message = 'Nightly Maintenance Completed'
                        AND x.NetObjectID = ST.NetObjectID
                        ORDER BY x.EventTime)
WHERE
    (ST.EventType = '5100' OR ST.EventType = '5102')
    AND ST.Message = 'Starting Nightly Maintenance'
    AND ST.EventTime > ADDDAY(-7,GETUTCDATE())
ORDER BY ST.EventTime DESC

SELECT Distinct
TOLOCAL(ST.EventTime) AS [Start Time]
,TOLOCAL(ET.EventTime) AS [Finish Time]
,CONCAT(--Downtime formatted  
        (CASE WHEN (SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60/60) >= 1 --Hours  
            THEN CONCAT(SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60/60%24, 'h ') ELSE '' END),  
        (CASE WHEN (SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60) >= 1 --Minutes  
            THEN CONCAT(SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))/60%60, 'm ') ELSE '' END),  
        (CASE WHEN (SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))) >= 1 --Seconds  
            THEN CONCAT(SECONDDIFF(ST.EventTime,ISNULL(ET.EventTime, GETUTCDATE()))%60, 's ') ELSE '' END)) AS [Duration]
FROM Orion.Events ST
LEFT JOIN Orion.Events ET ON ET.NetObjectID = ST.NetObjectID 
    AND ET.EventTime = (SELECT TOP 1 x.EventTime FROM Orion.Events x WHERE
                        x.EventTime >= ST.EventTime 
                        AND x.Message = 'Nightly Maintenance Completed'
                        AND x.NetObjectID = ST.NetObjectID
                        ORDER BY x.EventTime)
WHERE
   ST.Message = 'Starting Nightly Maintenance'
    AND ST.EventTime > ADDDAY(-7,GETUTCDATE())
ORDER BY ST.EventTime DESC