touch "$(date +%F) filename.txt"
creates file named 2021-12-06 filename.txt
touch "$(date) filename.txt"
creates file names Mon Dec 6 20:38:53 EST 2021 filename.txt
touch "$(date +%F) filename.txt"
creates file named 2021-12-06 filename.txt
touch "$(date) filename.txt"
creates file names Mon Dec 6 20:38:53 EST 2021 filename.txt