Today I needed to make a backup of some config. I wanted to add a timestamp so that I knew when the backup was made. This would make unique backups easy, and I could tell when they were made.
cp configfile configfile.backup.$(date %s)
If you want to decrypt the timestamp into something more human readable. You can list backup files, strip out the timestamp, and then convert it to a human readable date.
/bin/ls | grep backup | sed 's/configfile.backup.//' | xargs -I {} date -d @{}
or just throw it to the date command by hand.
date -d @1755895402