Insert the current Date and Time in Notepad or Notepad++

Notepad
Hit F5.


Notepad++
Install TextFX from Plugins menu.

You will now find TextFX > TextFX Insert > Date & Time - short format, which will insert a string in the exact same format

You can then bind it to a keyboard shortcut in Settings > Shortcut Mapper... > Plugin Commands. Look for I:Date & Time - short format in the mappings

http://stackoverflow.com/questions/27950710/in-notepad-how-can-i-insert-the-current-date-and-time