When I start the server on port 8080 it doesn't give me an error, but when I am trying to browse the http://localhost:8080/nowjs/now.js
the server raises an error:
[RangeError: Maximum call stack size exceeded]
undefined
I tried the same with socket.io and it worked fine.
Hmm, if now.js uses date.js, maybe your issue lies here. What the link says is that date.js tries to set a toString to Date prototype, but when toString is already defined, you get the circular reference mentioned in the other answers.
Basically, they say that in date.js, you change
Date.prototype._toString=Date.prototype.toString
to
if(Date.prototype._toString==undefined) {Date.prototype._toString=Date.prototype.toString;}
I hope it will help someone. It helped me.