>1. Open a new NotePad document
>2. Put ".LOG" as the first line
>3. Save the document
>
>Now, every time you open the document with NotePad, it will automatically append the current date/time.

Got it on second time... and even when they insert a cool feature, they have to screw it up...

1) .log doesn't work, it must be .LOG

2) it's time/date, not date/time with my system settings... in which there's nothing to indicate whether a datetime should be displayed with date or time first, they are set independently and the order is not set at all.

Here's how I was doing that for years:

#define cr chr(13)
#define c_log "the.log"
SET DATE YMD
set hours to 24
_screen.Visible=.t.
IF FILE(c_log)
	t=FDATE(c_log,1)
	ltClosed=TEXTMERGE([-- closed at <<t>>])+cr+cr+cr
ELSE
	ltClosed=""
endif
*-- TEXT BLOCK BEGIN
TEXT TO  cBuf NOSHOW TEXTMERGE PRETEXT 0
 <<ltClosed>><<SYS(0)>> <<DATETIME()>>
ENDTEXT
*-- TEXT BLOCK END
*[2014/02/18 11:48:54] nDragan - I just like macdesktop, works nice with two monitors
=strtofile(cr+cr+cBuf, c_log,1)
modify file (c_log) range 1e6, 1e6 nowait in macdesktop