I often need timestamp on the commandline or in scripts to save files with the exact time.

In the shell you can easy get a unix timestamp when you enter the following command:

date +%s

You can now simple save a mysqldump from with the exact time in the filename.

mysqldump DATABSE > DATABASE-`date +%s`.sql

Also you are able to create a bash/zsh alias for the timestamp. Just put the follwing line in your shell configuration:

alias timestamp = date +%s

Good Night, Daniel