insert creation date in the name of a file

DEVONthink Automation
19

Welcome @sunnySloth

Neither of these options are possible via placeholders, only scripting.
Note: Many date renaming scripts have been posted on the forums over the years.

Here is one approach with a teaching edition AppleScript example…

tell application id "DNtp"
	repeat with thisRecord in (selection as list)
		set recordName to (name of thisRecord)
		set creationDate to (creation date of thisRecord)
		
		set thisYear to year of creationDate as string
		set thisMonth to month of creationDate as integer -- As string produces the name of the month.
		set thisDay to day of creationDate as string
		set thisHour to hours of creationDate
		set thisMinute to minutes of creationDate
		set thisSecond to seconds of creationDate
		
		set thisYear to (characters 3 thru 4 of thisYear) as string
		
		set titleDateString to (thisYear & thisMonth & thisDay & thisHour & thisMinute & thisSecond & "_")
		set name of thisRecord to titleDateString & recordName
	end repeat
end tell

From Script Editor, save this script in ~/Library/Application Scripts/com.devon-technologies.think3/Menus and you can use it on selected files from DEVONthink’s Script menu.