Remove Dates from table t-sql I need the table to go from this:

 CalanderDateTime   PtID      EventDateTime    GapinMinutes
 2017-09-23 08:34   NULL          NULL              NULL
 2017-09-23 08:35   NULL          NULL              NULL
 2017-09-23 08:36   NULL          NULL              NULL
 2017-09-23 08:37    1      2017-09-23 08:37        1
 2017-09-23 08:38    1      2017-09-23 08:38        4
 2017-09-23 08:39  NULL          NULL             NULL
 2017-09-23 08:40  NULL          NULL             NULL
 2017-09-23 08:41  NULL          NULL             NULL
 2017-09-23 08:42  NULL          NULL             NULL
 2017-09-23 08:43    1      2017-09-23 08:43       3
 2017-09-23 08:44  NULL          NULL             NULL
 2017-09-23 08:45  NULL          NULL             NULL
 2017-09-23 08:46  NULL          NULL             NULL


to this:

CalanderDateTime   PtID      EventDateTime    GapinMinutes
 2017-09-23 08:34   NULL          NULL              NULL
 2017-09-23 08:35   NULL          NULL              NULL
 2017-09-23 08:36   NULL          NULL              NULL
 2017-09-23 08:37    1      2017-09-23 08:37        1
 2017-09-23 08:38    1      2017-09-23 08:38        4
 2017-09-23 08:43    1      2017-09-23 08:43        3
 2017-09-23 08:44  NULL          NULL             NULL
 2017-09-23 08:45  NULL          NULL             NULL
 2017-09-23 08:46  NULL          NULL             NULL


In this example i would want the next 4 rows removed from the row where 4 is shown in the 'GapinMinutes' column (but this can be any number > 3 and therefore whatever number of rows removed is based on the number shown in the 'GapinMinutes' column, so if the column has a 5, remove the next five rows, if its a 7 remove the next 7 rows, if its a 10, remove the next 10 rows but if its a a number &lt;= 3, keep the next 1,2 or 3 rows...

Here's the script i have so far:

With VentHours (ptID, t, ET, VGM)  AS  
(
    SELECT sig.PatientID, sig.Time,


        Case When sig.PatientID = LEAD(sig.PatientID) OVER (ORDER BY sig.PatientID, Sig.Time) AND DateDiff(MINUTE,sig.Time,LEAD(sig.Time) OVER (ORDER BY sig.PatientID, Sig.Time)) between 0 and 720 THEN DateDiff(MINUTE,sig.Time,LEAD(sig.Time) OVER (ORDER BY sig.PatientID, Sig.Time)) ELSE 0 END Vent_Gap_Mins

        FROM GCUH_Reporting.dbo.VIEW_GCUH_Vent_Signals sig 
        inner join GCUH_Archive.dbo.Patients p ON sig.PatientID = p.PatientID
),

JoinTime as 
(
    Select *
    from GCUH_Reporting.dbo.AUX_DateDimension ts
    left outer join VentHours vh ON convert(DateTime,ts.DateTime) = convert(DateTime,vh.t) 
)

select jt.DateTime, jt.ptid, jt.et, jt.vgm



from JoinTime jt

--where  jt.ptID   is not null

order by jt.DateTime
This is Sql server 2008 script.i think it can be easily translated to other rdbms.

Secondly your sample data is wrong.It should be 08:43 instead of 09:43

create table #t (CalanderDateTime datetime, PtID int,EventDateTime  datetime,GapinMinutes int)
insert into #t VALUES
 ('2017-09-23 08:34',   NULL,          NULL         ,  NULL)
 ,('2017-09-23 08:35',   NULL,          NULL         ,  NULL)
 ,('2017-09-23 08:36',   NULL,          NULL         ,  NULL)
 ,('2017-09-23 08:37',    1  ,    '2017-09-23 08:30'   ,  1 )
 ,('2017-09-23 08:38',    1  ,    '2017-09-23 08:35'   ,  4 )
 ,('2017-09-23 08:39',  NULL ,         NULL          ,NULL  )
 ,('2017-09-23 08:40',  NULL ,         NULL          ,NULL  )
 ,('2017-09-23 08:41',  NULL ,         NULL          ,NULL  )
 ,('2017-09-23 08:42',  NULL ,         NULL          ,NULL  )
 ,('2017-09-23 08:43',    1  ,    '2017-09-23 09:40'   , 3  )
 ,('2017-09-23 08:44',  NULL ,         NULL          ,NULL  )
 ,('2017-09-23 08:45',  NULL ,         NULL          ,NULL  )
 ,('2017-09-23 08:46',  NULL ,         NULL          ,NULL  )

 ;WITH CTE as
 (
  select * 
 ,ROW_NUMBER()OVER(ORDER BY CalanderDateTime)rn
 from #t
 )
,CTE1 AS(
 select c.rn from cte c
cross apply(select rn from cte c1 
 where c1.GapinMinutes is not null and c1.GapinMinutes&gt;3 and  
 (c.rn&gt;c1.rn and c.rn&lt;(c1.rn+c1.GapinMinutes+1)) )ca
 )
 select * from cte c
 where not exists (select rn from cte1  c1 where c.rn=c1.rn)

 drop TABLE #t