The problem is while running for one day continuously the data is not coming to cloud server.
We have to manually RESET the board[Arduino UNO] and then again the program runs as usual.
A program resetting itself before it locks up will fix that problem only. If you're only going to fix the one problem, you'd be better to first try fix the actual problem, rather than mask it.
From the receiving logs at the cloud server, can you confirm that the sensor device runs for a specific amount of time before stopping? Like, it could be 86400 seconds (full day) but it could be some other nearby interval like 65536 seconds or 32 hours or... whatever.
It does sound a bit like there is time wraparound from eg 86399 to 0 seconds or 23.999 to 0.000 hours or "23:59:59" to "00:00:00", and that a timeout is implemented like:
WaitUntil = CurrentTime + HowLongToWait
Do Until CurrentTime > WaitUntil
'wait up to HowLongToWait for something to happen
Loop
Is there anything like that in your code?