[bash] Passing argument to alias in bash

Usually when I want to pass arguments to an alias in Bash, I use a combination of an alias and a function like this, for instance:

function __t2d {                                                                
         if [ "$1x" != 'x' ]; then                                              
            date -d "@$1"                                                       
         fi                                                                     
} 

alias t2d='__t2d'