Ubuntu – Bypass the yes/no prompt in ‘apt-get upgrade’

This should work fine for you. The date command is all that is needed.

alias cryptodoc="cd ~/Desktop/ && 7z a -pSome_Pass -r ~/Desktop/$(date +%Y%m%d)_Documents_Backup.7z ~/Documents/* 2>/dev/null"

the command for date +%Y%m%d means, run date, then + means format, then %Y means YYYY, %m means MM and %d means DD. Having the $( ) around the date command means to run it at the time of the command.

Hope this helps!

The date commands are evaluated when you declare the alias.

Here's an example alias t:

$ alias t="echo \"$(date +%k%M)\""
$ alias t
alias t='echo "1357"'

You can fix this by using single quotes:

$ alias t='echo "$(date +%k%M)"'
$ alias t
alias t='echo "$(date +%k%M)"'

For more info, see Difference between single and double quotes in Bash

Or if the command doesn't need to be an alias, use a function instead:

$ function t { echo "$(date +%k%M)"; }
$ declare -f t
t () 
{ 
    echo "$(date +%k%M)"
}

Or a script:

#!/bin/sh
echo "$(date +%k%M)"

Update, per recent edit

$ alias t='echo '$(date +%k%M)''
$ alias t
alias t='echo 1400'

Think of that alias definition as three strings:

1. One single-quoted string: 'echo '
2. One unquoted string: $(date +%k%M)
3. One single-quoted null string: ''