I just wrote a short AppleScript that can set the creation and modification dates of a Keynote presentation to the current date/time without needing any external commands. It prompts you for the file, and immediately changes those two date/time stamps that are verified with a Get Info on that file.
Copy/paste the following into Apple's Script Editor, click the hammer icon to compile and the Run button to execute it:
use framework "Foundation"
use AppleScript version "2.5"
use scripting additions
property ca : current application
set myPath to POSIX path of (choose file of type "key")
set now to ca's NSDate's now()
set fm to ca's NSFileManager's defaultManager()
set adict to ca's NSDictionary's alloc()'s initWithObjects:{now, now} forKeys:{ca's NSFileCreationDate, ca's NSFileModificationDate}
try
fm's setAttributes:adict ofItemAtPath:myPath |error|:(reference)
on error
display dialog "Failed to set creation and modfication dates." with title "Error Result"
end try
return
Tested: macOS Sequoia v15.0.1 with a Keynote v14.2 presentation.
It would be easy to write an Apple Shortcut Quick Action that allows one to right-click on a file and apply the same result in a Run AppleScript action.