// This is how I used it:
// $ node bash-history-to-zsh-history.js >> ~/.zsh_history

var fs   = require("fs");
var a    = fs.readFileSync("bash_history");
var time = Date.now();

a.toString().split("\n").forEach(
   function(line) {
      console.log(": "+ (time++) + ":0;" + line);
   }
);