annoying: A random year between 2000 and 2045 is used for cal command.

[zeroby0]

function cal() {
    if [ $# -eq 0 ]; then # If no arguments
        /usr/bin/cal -m $(date +%b) $(( ((RANDOM<<15)|RANDOM) % 45 + 2000 ));
    else
        /usr/bin/cal $(( ((RANDOM<<15)|RANDOM) % 45 + 2000 ));
    fi;
}

A random year between 2000 and 2045 is used for cal command.

https://github.com/zeroby0/pranks