# Note: These are backticks, not quotes.
# They are on the same key as your tilde ~.
ls > `date %Y-%m-%d.`txt
To get the possible formatting options, run the man date command.
In Dos it is pretty easy too, once you know the trick.
dir > %date:~-4,4%-%date:~-7,2%-%date:~-10,2%.txt
The %date% environment variable contains the current date. Go ahead, test it. Pop open a command prompt and run echo %date%. The ":~-4,4" part does the cool thing. ":~" says "we want a substring". The "-" says "work from the end of the string backwards. The "4," says start at the fourth character, and the final "4" says give me four characters.
|Day of week (3 letter abbr.)||%date:~0,3%|
|Year (2 digits)||%date:~-2,2%|
|Year (4 digits)||%date:~-4,4%|