Hello! I was having this problem too, so I created a work around! Hope this works for you. It unfortunately only will work on the mac desktop, not the numbers app for iOS. I assume the original writer has long since not found a use for this, but if someone else does then that's good!
My solution was to create a service and then give it a hot key.
1. Open Automator.app from your applications folder, select "service" as your type of project, then select choose.
2. Select "No Input" in the drop down box labeled "Service receives selected"
3. Select "Numbers" in the drop down menu directly beside the previous one, or if it is not directly available, select other and select numbers in your applications folder.
4. Select "Library" of the left menu in the top left of the window. In the search bar type "apple"
5. Drag "Run AppleScript" to the main grey area until you see a plus sign.
6. You should see this.
7. Copy the following text between the ++++++'s, but without copying the ++++++'s. Paste it where it says (* Your script goes here *). Make sure to leave the rest of the text that is there already (on run... return input... end run, etc).
++++++
tell application "Numbers"
set the_date to current date
activate
tell table 1 of the active sheet of document 1 to set the value of cell 1 of the selection range to (the_date as string)
end tell
++++++
You should have something that looks like this.
8. Hit the hammer:
Your code will compile and check that it is not in violation. If all goes well it should look like this.
(if all does not go well, you are either using too old a version of automator, or your computer's operating system is too old. At the time of writing this, this was created on OSX El Capitan. If you can, update to this operating system (link here) or later and try again. If you are trying this and your operating system is so far advanced that this isn't working, I have no advice for you except why are you reading this really really old forum post??)
9. Save the file and name it what ever you like, I chose to set mine to "TimeStamp".
10. Open System Preferences.
11. Select Keyboard.
12. Select Services from the left menu.
13. Select Shortcuts from the top menu.
14. Under the General Tab, select the title of your service, mine is titled "TimeStamp"
15. Select the button that says "add shortcut"
16. Hold down the key combination that you would like to use to activate your script.
I chose [ Shift key + Control Key + Option Key + Command Key + T Key ] as is laid out on the keyboard.
(FYI: from left to right in the image the symbols actually should be read Ctrl + Alt + Shift + Cmd + T)
17. That's it! Open numbers and check that in the services fly out window that your service has it's shortcut listed next to it.
Now all that's left is every time you want to add a time stamp to something, hold down shift + Ctrl + option + cmd + T and your cell will be filled with the current time. This time will be permanent, so it will not update then next time you open the document.
Hope this was what you were looking for!
