I have used data validation list to enter time in cells with reference
to A1 current time =TIME(HOUR(NOW()),MINUTE(NOW()),SECOND(NOW()))

When the excel sheet is minimised the work book is inactive and the
time is not updated, it shows the previous time in which its minimised

for eg if i minimise at 11:36:32 AM and open sheet at 11:39:32 AM

the start time should be 11:39:32 AM and end time should be the time at
which the task ends, but excel takes the start time as 11:36:32 AM and
end time as 11:39:32 AM

please help to solve the problem