Simple UID generation with CoffeeScript

This is an overly simple function to generate unique ID's using CoffeeScript based on the current time.

generateId = ->
    chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
    today = new Date()
    result = today.valueOf().toString 16
    result += chars.substr Math.floor(Math.random() * chars.length), 1
    result += chars.substr Math.floor(Math.random() * chars.length), 1
    return result

The two last random characters are appended to minimize collisions.

I'm using it on Counting.to and on the Zalando System App.