How do I automatically insert the time & date last modified into a Notepad++ document? I have found a question about automatically inserting the current time, but it appears to be about a much earlier version and the upvoted answers no longer work. Ideally I'd like not to have to remember to do this at the end of every editing session. . .
TextFX allows you to do this manually and you can assign a keyboard shortcut for it as well. See the answers to this question for details.
Plugin Central has a couple of plugins you could try for automatic date/time insertion:
Insertion Version 2.1 (ANSI) by Don HO: Insertion of current file name and date & time. Auto-close the html/xml tag.
Log plugin Version 1.0 (Unicode) by Nicholas Heckman: Log plugin allows Notepad++ has [sic] one of MS Notepad basic features : Append the date/time at the end of file after a file is opened in Notepad++, if file begins with ".LOG".