SerendipitousNomads

I need some Schengen visa assistance and I can't find anything regarding my situation in any searches elsewhere so hopefully someone here might be able to help me out.
I am Australian and arrived in the Schengen zone at the end of July.
Just before the end of my 90 day period, I applied and was granted an extention to my visa in Portugal. This allowed me to stay for an extra 90 days, only in Portugal. (Type C Visitor visa).
Now, following this visa, it will be 180 days since I first entered the Schengen zone.
I found information online that states "periods of stay authorized under a long stay visa shall not be taken into account in the calculation of the duration of stay" in the schengen.
So therefore, it is my understanding that I should be able to start a new 180 day period when my current visa expires.
I wish to visit the Netherlands to see family for a period of one month before leaving to go back to Australia.
Does anyone have experience starting a new 180 day period whilst already I the schengen? Do you have to take your passport to an immigration authority to be stamped for a new period and if so, where do you go?
Or to start a new period, do you have to exit and re-enter the schengen zone?

DebitNM

While this takes a bit of a learning curve to use, it works well under most circumstances; not sure with the special extra 90 days Visa.

http://ec.europa.eu/dgs/home-affairs...ulator_en.html

DebitNM

Just saw this one, I've not used it, seems a bit less complicated -
http://www.visacalc.com/