Static date & time in B, when data entered in A

Hi all!

I am in need of some help for a problem.

I would like to have a cell that tells me the date and time that data was entered into a specific cell.
Obviously we know that NOW and TODAY can do this - but the only problem is that they aren't static, and will change to be the current time whenever the document is opened or calculations are run.

What I want is for a client COVID test result to be entered when we receive the report, and when that is done, the cell in the next column & same row, will display the date and time this was done.
The thing I'm having trouble with is figuring out how to keep it static, so it will only display the time the result was entered (without having to type this manually every single time).

I wasn't sure which forum to post this in but I imagine the solution to this may instead be some VBA/macro, so I will post over there instead if that is the case.

Any help you have is appreciated

Jbok

Hi Wayne, Glenn,

I Wasn't sure about attaching a sample due to me working in NHS in infection control. I know there'd be no personal data but i'm not even sure we're allowed to put trust documents anywhere externally so I didn't want to risk it.
Either way, thanks for your posts, this seems to have worked! Many thanks for your help!

Jamie

Ah yes I already did that just before I read your comment!

I was looking for the option to close/mark as solved so thanks for that too!
Have a great day, both!

Jamie