So, is there any particular method for you to use in order to come up with the date or is it a mere speculation?
Yes PR is not that important..but we can't ignore it PR plays important role in getting ads for websites to generate revenue
If you want to impress do this... make your prediction and put it in a password protected zip file and distribute that file all over the internet. When the update takes place then release the password so people can verify you were correct. Ok... IMPRESS US