Convesion of number into time and subtracting from another Time value

[sgowri7]

Hi all,

I have Due DateTime of a record and the required TAT within which the record must be complated (eg. 6 hrs, 12 hrs, 48 hrs etc.).

Now, I would like to obtain the Received DateTime value from the above -

logically speaking [Due DateTime] - Time of(TAT).

but unable to represent this in the formula format in query - MS ACcess.

Can anyone please help me in this regard?

Thank you,
SGS