When to fund? (Kickstarter/Indiegogo)

I have my game Zombie Nauts and I plan on kickstarting it or using Indiegogo to pay for advertising and webhosting. When would be a good time to do this? When the game is completely finished? When it is halfway? When it is in beta? Or the alpha stage it is in now?

I’m not really stressing over this but my mind has been rolling this question over and over in my head all day.

So, when is the best time and what is the best strategy?