General :: Set What Should Happen In Terminal On A Certain Command?

If I execute

cal 2013

in terminal, it echoes the calendar for the year 2013. For the matter of fun, I'd like the terminal to echo

This year won't come.

How should I do this? I tried adding it as an alias to .bashrc, but I cannot create aliases with spaces.

EDIT:

The final solution:

echo "cal() { if [[ $@ > "2012" ]]; then command echo "This year won't come."; else command cal "$@"; fi; }" >> ~/.profile && source ~/.profile