I want to keep =now() from updating

[95marine]

I am trying to use the date & time to generate a ticket number. I want the date & time to update only when prompted by a macro. If the time & date updates every time the spreadsheet is opened or any time the user interacts with the spreadsheet, the ticket number will update as well and this is completely defeating my purpose.

I have a spreadsheet that is a brief example of what I am trying to do.

Thanks in advance for any help.