Brexit 90 days problem

90 day stay all about the whole 'Schengen area not just Spain', here is web page  which explains best, with a link to a good calculator. 

Where it gets slightly complicated the EU definition of ’90 days is within any 180-day period’ & best to think of the 180 days as a moveable timeframe rather than a fixed 180-day period. The 180 days are counted backwards from the date of arrival or departure from the Schengen area.

 https://www.frenchentree.com/brexit/eu-90-180-day-rule-heres-how-it-works/

Thanks for the replies, but still not sure if 1 month in and 1month out applies is ok. I am sure I am not the only stupid one concerning this topic. 

OK - you stay 30 days Jan, another 30 in March & 30 days May, that's 90 days from first visit, 180 days counted from the start of Jan. Once day 181 hits, the count resets itself, in this example would be July. 

https://www.nomadicmatt.com/travel-blogs/how-to-legally-stay-in-europe-for-more-than-90-days/

Here's a calculator I think simplifies the 90/180 issue 

Shengen Days

Thank you Holaitsdavid this is just as I thought.But people are so negative about this. This is what I have been doing but coming up to the end of my 90 days.Once again Thank you 

Put your requirements into the Schengen calculator it will tell you whether you can do it