How to minus between two time in a column ?

Question

I want difference between two time ,

Create table #conIssuance (ID int,CID varchar(50),E_Date date,E_Time Time(7),QTY int)

Insert into #conIssuance values (11101,'Saver' ,'2023-11-07','08:00',1)
Insert into #conIssuance values (11102,'Saver' ,'2023-11-07','08:10',1)
Insert into #conIssuance values (11103,'Saver' ,'2023-11-07','08:18',1)
Insert into #conIssuance values (11104,'Saver' ,'2023-11-07','08:25',1)
Insert into #conIssuance values (11105,'Army' ,'2023-11-07','08:35',1)

Output

Last row will be subtract from 8:50

Answer 1

Check this query:

select ID, CID, E_Date, datediff(minute, E_Time, coalesce(lead(E_Time) over (order by E_Date, E_Time), '08:50')) as Minutes
from #conIssuance 
order by E_Date, E_Time

(Assuming that the time does not pass the midnight).